diff --git a/src/printer_lyb.c b/src/printer_lyb.c
new file mode 100644
index 0000000..0d95bbd
--- /dev/null
+++ b/src/printer_lyb.c
@@ -0,0 +1,1045 @@
+/**
+ * @file printer_lyb.c
+ * @author Michal Vasko <mvasko@cesnet.cz>
+ * @brief LYB printer for libyang data structure
+ *
+ * Copyright (c) 2020 CESNET, z.s.p.o.
+ *
+ * This source code is licensed under BSD 3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://opensource.org/licenses/BSD-3-Clause
+ */
+
+#include "lyb.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "common.h"
+#include "compat.h"
+#include "log.h"
+#include "printer.h"
+#include "printer_internal.h"
+#include "tree_data_internal.h"
+#include "tree_schema.h"
+#include "tree_schema_internal.h"
+
+/**
+ * @brief Hash table equal callback for checking hash equality only.
+ */
+static int
+lyb_hash_equal_cb(void *UNUSED(val1_p), void *UNUSED(val2_p), int UNUSED(mod), void *UNUSED(cb_data))
+{
+    /* for this purpose, if hash matches, the value does also, we do not want 2 values to have the same hash */
+    return 1;
+}
+
+/**
+ * @brief Hash table equal callback for checking value pointer equality only.
+ */
+static int
+lyb_ptr_equal_cb(void *val1_p, void *val2_p, int UNUSED(mod), void *UNUSED(cb_data))
+{
+    struct lysc_node *val1 = *(struct lysc_node **)val1_p;
+    struct lysc_node *val2 = *(struct lysc_node **)val2_p;
+
+    if (val1 == val2) {
+        return 1;
+    }
+    return 0;
+}
+
+/**
+ * @brief Check that sibling collision hash is safe to insert into hash table.
+ *
+ * @param[in] ht Hash table.
+ * @param[in] sibling Hashed sibling.
+ * @param[in] ht_col_id Sibling hash collision ID.
+ * @param[in] compare_col_id Last collision ID to compare with.
+ * @return LY_SUCCESS when the whole hash sequence does not collide,
+ * @return LY_EEXIST when the whole hash sequence sollides.
+ */
+static LY_ERR
+lyb_hash_sequence_check(struct hash_table *ht, struct lysc_node *sibling, int ht_col_id, int compare_col_id)
+{
+    int j;
+    struct lysc_node **col_node;
+
+    /* get the first node inserted with last hash col ID ht_col_id */
+    if (lyht_find(ht, &sibling, lyb_hash(sibling, ht_col_id), (void **)&col_node)) {
+        /* there is none. valid situation */
+        return LY_SUCCESS;
+    }
+
+    lyht_set_cb(ht, lyb_ptr_equal_cb);
+    do {
+        for (j = compare_col_id; j > -1; --j) {
+            if (lyb_hash(sibling, j) != lyb_hash(*col_node, j)) {
+                /* one non-colliding hash */
+                break;
+            }
+        }
+        if (j == -1) {
+            /* all whole hash sequences of nodes inserted with last hash col ID compare_col_id collide */
+            lyht_set_cb(ht, lyb_hash_equal_cb);
+            return LY_EEXIST;
+        }
+
+        /* get next node inserted with last hash col ID ht_col_id */
+    } while (!lyht_find_next(ht, col_node, lyb_hash(*col_node, ht_col_id), (void **)&col_node));
+
+    lyht_set_cb(ht, lyb_hash_equal_cb);
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Hash all the siblings and add them also into a separate hash table.
+ *
+ * @param[in] sibling Any sibling in all the siblings on one level.
+ * @param[out] ht_p Created hash table.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_hash_siblings(struct lysc_node *sibling, struct hash_table **ht_p)
+{
+    struct hash_table *ht;
+    const struct lysc_node *parent;
+    const struct lys_module *mod;
+    int i, j;
+
+    ht = lyht_new(1, sizeof(struct lysc_node *), lyb_hash_equal_cb, NULL, 1);
+    LY_CHECK_ERR_RET(!ht, LOGMEM(sibling->module->ctx), LY_EMEM);
+
+    parent = lysc_data_parent(sibling);
+    mod = sibling->module;
+
+    sibling = NULL;
+    /* ignore features so that their state does not affect hashes */
+    while ((sibling = (struct lysc_node *)lys_getnext(sibling, parent, mod->compiled, LYS_GETNEXT_NOSTATECHECK))) {
+        /* find the first non-colliding hash (or specifically non-colliding hash sequence) */
+        for (i = 0; i < LYB_HASH_BITS; ++i) {
+            /* check that we are not colliding with nodes inserted with a lower collision ID than ours */
+            for (j = i - 1; j > -1; --j) {
+                if (lyb_hash_sequence_check(ht, sibling, j, i)) {
+                    break;
+                }
+            }
+            if (j > -1) {
+                /* some check failed, we must use a higher collision ID */
+                continue;
+            }
+
+            /* try to insert node with the current collision ID */
+            if (!lyht_insert_with_resize_cb(ht, &sibling, lyb_hash(sibling, i), lyb_ptr_equal_cb, NULL)) {
+                /* success, no collision */
+                break;
+            }
+
+            /* make sure we really cannot insert it with this hash col ID (meaning the whole hash sequence is colliding) */
+            if (i && !lyb_hash_sequence_check(ht, sibling, i, i)) {
+                /* it can be inserted after all, even though there is already a node with the same last collision ID */
+                lyht_set_cb(ht, lyb_ptr_equal_cb);
+                if (lyht_insert(ht, &sibling, lyb_hash(sibling, i), NULL)) {
+                    LOGINT(sibling->module->ctx);
+                    lyht_set_cb(ht, lyb_hash_equal_cb);
+                    lyht_free(ht);
+                    return LY_EINT;
+                }
+                lyht_set_cb(ht, lyb_hash_equal_cb);
+                break;
+            }
+            /* there is still another colliding schema node with the same hash sequence, try higher collision ID */
+        }
+
+        if (i == LYB_HASH_BITS) {
+            /* wow */
+            LOGINT(sibling->module->ctx);
+            lyht_free(ht);
+            return LY_EINT;
+        }
+    }
+
+    /* change val equal callback so that the HT is usable for finding value hashes */
+    lyht_set_cb(ht, lyb_ptr_equal_cb);
+
+    *ht_p = ht;
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Find node hash in a hash table.
+ *
+ * @param[in] ht Hash table to search in.
+ * @param[in] node Node to find.
+ * @param[out] hash_p First non-colliding hash found.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_hash_find(struct hash_table *ht, struct lysc_node *node, LYB_HASH *hash_p)
+{
+    LYB_HASH hash;
+    uint32_t i;
+
+    for (i = 0; i < LYB_HASH_BITS; ++i) {
+        hash = lyb_hash(node, i);
+        if (!hash) {
+            LOGINT_RET(node->module->ctx);
+        }
+
+        if (!lyht_find(ht, &node, hash, NULL)) {
+            /* success, no collision */
+            break;
+        }
+    }
+    /* cannot happen, we already calculated the hash */
+    if (i == LYB_HASH_BITS) {
+        LOGINT_RET(node->module->ctx);
+    }
+
+    *hash_p = hash;
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Write LYB data fully handling the metadata.
+ *
+ * @param[in] out Out structure.
+ * @param[in] buf Source buffer.
+ * @param[in] count Number of bytes to write.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_write(struct ly_out *out, const uint8_t *buf, size_t count, struct lyd_lyb_ctx *lybctx)
+{
+    LY_ARRAY_SIZE_TYPE u;
+    struct lyd_lyb_subtree *full, *iter;
+    ssize_t r, to_write;
+    uint8_t meta_buf[LYB_META_BYTES];
+
+    while (1) {
+        /* check for full data chunks */
+        to_write = count;
+        full = NULL;
+        LY_ARRAY_FOR(lybctx->subtrees, u) {
+            /* we want the innermost chunks resolved first, so replace previous full chunks */
+            if (lybctx->subtrees[u].written + to_write >= LYB_SIZE_MAX) {
+                /* full chunk, do not write more than allowed */
+                to_write = LYB_SIZE_MAX - lybctx->subtrees[u].written;
+                full = &lybctx->subtrees[u];
+            }
+        }
+
+        if (!full && !count) {
+            break;
+        }
+
+        /* we are actually writing some data, not just finishing another chunk */
+        if (to_write) {
+            r = ly_write(out, (char *)buf, to_write);
+            if (r < to_write) {
+                return LY_ESYS;
+            }
+            lybctx->byte_count += r;
+
+            LY_ARRAY_FOR(lybctx->subtrees, u) {
+                /* increase all written counters */
+                lybctx->subtrees[u].written += r;
+                assert(lybctx->subtrees[u].written <= LYB_SIZE_MAX);
+            }
+            /* decrease count/buf */
+            count -= r;
+            buf += r;
+        }
+
+        if (full) {
+            /* write the meta information (inner chunk count and chunk size) */
+            meta_buf[0] = full->written & 0xFF;
+            meta_buf[1] = full->inner_chunks & 0xFF;
+
+            r = ly_write_skipped(out, full->position, (char *)meta_buf, LYB_META_BYTES);
+            if (r < 0) {
+                return LY_ESYS;
+            }
+            /* these bytes were already counted */
+
+            /* zero written and inner chunks */
+            full->written = 0;
+            full->inner_chunks = 0;
+
+            /* skip space for another chunk size */
+            r = ly_write_skip(out, LYB_META_BYTES, &full->position);
+            if (r < LYB_META_BYTES) {
+                return LY_ESYS;
+            }
+            lybctx->byte_count += r;
+
+            /* increase inner chunk count */
+            for (iter = &lybctx->subtrees[0]; iter != full; ++iter) {
+                if (iter->inner_chunks == LYB_INCHUNK_MAX) {
+                    LOGINT(lybctx->ctx);
+                    return LY_EINT;
+                }
+                ++iter->inner_chunks;
+            }
+        }
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Stop the current subtree - write its final metadata.
+ *
+ * @param[in] out Out structure.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_write_stop_subtree(struct ly_out *out, struct lyd_lyb_ctx *lybctx)
+{
+    ssize_t r;
+    uint8_t meta_buf[LYB_META_BYTES];
+
+    /* write the meta chunk information */
+    meta_buf[0] = LYB_LAST_SUBTREE(lybctx).written & 0xFF;
+    meta_buf[1] = LYB_LAST_SUBTREE(lybctx).inner_chunks & 0xFF;
+
+    r = ly_write_skipped(out, LYB_LAST_SUBTREE(lybctx).position, (char *)&meta_buf, LYB_META_BYTES);
+    if (r < 0) {
+        return LY_ESYS;
+    }
+    /* do not count these bytes */
+
+    LY_ARRAY_DECREMENT(lybctx->subtrees);
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Start a new subtree - skip bytes for its metadata.
+ *
+ * @param[in] out Out structure.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_write_start_subtree(struct ly_out *out, struct lyd_lyb_ctx *lybctx)
+{
+    ssize_t r;
+    LY_ARRAY_SIZE_TYPE u;
+
+    if (!lybctx->subtrees) {
+        u = 0;
+    } else {
+        u = LY_ARRAY_SIZE(lybctx->subtrees);
+    }
+    if (u == lybctx->subtree_size) {
+        LY_ARRAY_CREATE_RET(lybctx->ctx, lybctx->subtrees, u + LYB_SUBTREE_STEP, LY_EMEM);
+        lybctx->subtree_size = u + LYB_SUBTREE_STEP;
+    }
+
+    LY_ARRAY_INCREMENT(lybctx->subtrees);
+    LYB_LAST_SUBTREE(lybctx).written = 0;
+    LYB_LAST_SUBTREE(lybctx).inner_chunks = 0;
+
+    /* another inner chunk */
+    for (u = 0; u < LY_ARRAY_SIZE(lybctx->subtrees) - 1; ++u) {
+        if (lybctx->subtrees[u].inner_chunks == LYB_INCHUNK_MAX) {
+            LOGINT(lybctx->ctx);
+            return -1;
+        }
+        ++lybctx->subtrees[u].inner_chunks;
+    }
+
+    r = ly_write_skip(out, LYB_META_BYTES, &LYB_LAST_SUBTREE(lybctx).position);
+    if (r < LYB_META_BYTES) {
+        return LY_ESYS;
+    }
+    lybctx->byte_count += r;
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Write a number.
+ *
+ * @param[in] num Number to write.
+ * @param[in] bytes Actual accessible bytes of @p num.
+ * @param[in] out Out structure.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_write_number(uint64_t num, size_t bytes, struct ly_out *out, struct lyd_lyb_ctx *lybctx)
+{
+    /* correct byte order */
+    num = htole64(num);
+
+    return lyb_write(out, (uint8_t *)&num, bytes, lybctx);
+}
+
+/**
+ * @brief Write a string.
+ *
+ * @param[in] str String to write.
+ * @param[in] str_len Length of @p str.
+ * @param[in] with_length Whether to precede the string with its length.
+ * @param[in] out Out structure.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_write_string(const char *str, size_t str_len, int with_length, struct ly_out *out, struct lyd_lyb_ctx *lybctx)
+{
+    int r;
+
+    if (!str) {
+        str = "";
+    }
+    if (!str_len) {
+        str_len = strlen(str);
+    }
+
+    if (with_length) {
+        /* print length on 2 bytes */
+        if (str_len > UINT16_MAX) {
+            LOGINT(lybctx->ctx);
+            return LY_EINT;
+        }
+        LY_CHECK_RET(lyb_write_number(str_len, 2, out, lybctx));
+    }
+
+    r = lyb_write(out, (const uint8_t *)str, str_len, lybctx);
+    if (r < 0) {
+        return LY_ESYS;
+    }
+    lybctx->byte_count += r;
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Print YANG module info.
+ *
+ * @param[in] out Out structure.
+ * @param[in] mod Module to print.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_model(struct ly_out *out, const struct lys_module *mod, struct lyd_lyb_ctx *lybctx)
+{
+    int r;
+    uint16_t revision;
+
+    /* model name length and model name */
+    if (mod) {
+        LY_CHECK_RET(lyb_write_string(mod->name, 0, 1, out, lybctx));
+    } else {
+        LY_CHECK_RET(lyb_write_string("", 0, 1, out, lybctx));
+    }
+
+    /* model revision as XXXX XXXX XXXX XXXX (2B) (year is offset from 2000)
+     *                   YYYY YYYM MMMD DDDD */
+    revision = 0;
+    if (mod && mod->revision) {
+        r = atoi(mod->revision);
+        r -= 2000;
+        r <<= 9;
+
+        revision |= r;
+
+        r = atoi(mod->revision + 5);
+        r <<= 5;
+
+        revision |= r;
+
+        r = atoi(mod->revision + 8);
+
+        revision |= r;
+    }
+    LY_CHECK_RET(lyb_write_number(revision, sizeof revision, out, lybctx));
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Print all used YANG modules.
+ *
+ * @param[in] out Out structure.
+ * @param[in] root Data root.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_data_models(struct ly_out *out, const struct lyd_node *root, struct lyd_lyb_ctx *lybctx)
+{
+    struct ly_set *set;
+    LY_ARRAY_SIZE_TYPE u;
+    LY_ERR ret = LY_SUCCESS;
+    struct lys_module *mod;
+    const struct lyd_node *node;
+    uint32_t i;
+
+    set = ly_set_new();
+    LY_CHECK_RET(!set, LY_EMEM);
+
+    /* collect all data node modules */
+    LY_LIST_FOR(root, node) {
+        if (!node->schema) {
+            continue;
+        }
+
+        mod = node->schema->module;
+        ly_set_add(set, mod, 0);
+
+        /* add also their modules deviating or augmenting them */
+        LY_ARRAY_FOR(mod->compiled->deviated_by, u) {
+            ly_set_add(set, mod->compiled->deviated_by[u], 0);
+        }
+        LY_ARRAY_FOR(mod->compiled->augmented_by, u) {
+            ly_set_add(set, mod->compiled->augmented_by[u], 0);
+        }
+    }
+
+    /* now write module count on 2 bytes */
+    LY_CHECK_GOTO(ret = lyb_write_number(set->count, 2, out, lybctx), cleanup);
+
+    /* and all the used models */
+    for (i = 0; i < set->count; ++i) {
+        LY_CHECK_GOTO(ret = lyb_print_model(out, set->objs[i], lybctx), cleanup);
+    }
+
+cleanup:
+    ly_set_free(set, NULL);
+    return ret;
+}
+
+/**
+ * @brief Print LYB magic number.
+ *
+ * @param[in] out Out structure.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_magic_number(struct ly_out *out, struct lyd_lyb_ctx *lybctx)
+{
+    int r;
+    uint32_t magic_number;
+
+    /* 'l', 'y', 'b' - 0x6c7962 */
+    ((char *)&magic_number)[0] = 'l';
+    ((char *)&magic_number)[1] = 'y';
+    ((char *)&magic_number)[2] = 'b';
+
+    r = ly_write(out, (char *)&magic_number, 3);
+    if (r < 3) {
+        return LY_ESYS;
+    }
+    lybctx->byte_count += 3;
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Print LYB header.
+ *
+ * @param[in] out Out structure.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_header(struct ly_out *out, struct lyd_lyb_ctx *lybctx)
+{
+    int r;
+    uint8_t byte = 0;
+
+    /* version, future flags */
+    byte |= LYB_VERSION_NUM;
+
+    r = ly_write(out, (char *)&byte, 1);
+    if (r < 1) {
+        return LY_ESYS;
+    }
+    lybctx->byte_count += 1;
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Print opaque prefixes.
+ *
+ * @param[in] out Out structure.
+ * @param[in] prefs Prefixes to print.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_opaq_prefixes(struct ly_out *out, const struct ly_prefix *prefs, struct lyd_lyb_ctx *lybctx)
+{
+    uint8_t count;
+    LY_ARRAY_SIZE_TYPE u;
+
+    if (prefs && (LY_ARRAY_SIZE(prefs) > UINT8_MAX)) {
+        LOGERR(lybctx->ctx, LY_EINT, "Maximum supported number of prefixes is %u.", UINT8_MAX);
+        return LY_EINT;
+    }
+
+    count = prefs ? LY_ARRAY_SIZE(prefs) : 0;
+
+    /* write number of prefixes on 1 byte */
+    LY_CHECK_RET(lyb_write(out, &count, 1, lybctx));
+
+    /* write all the prefixes */
+    LY_ARRAY_FOR(prefs, u) {
+        /* prefix */
+        LY_CHECK_RET(lyb_write_string(prefs[u].pref, 0, 1, out, lybctx));
+
+        /* namespace */
+        LY_CHECK_RET(lyb_write_string(prefs[u].ns, 0, 1, out, lybctx));
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Print opaque node.
+ *
+ * @param[in] opaq Node to print.
+ * @param[in] out Out structure.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_opaq(struct lyd_node_opaq *opaq, struct ly_out *out, struct lyd_lyb_ctx *lybctx)
+{
+    /* prefix */
+    LY_CHECK_RET(lyb_write_string(opaq->prefix.pref, 0, 1, out, lybctx));
+
+    /* namespace */
+    LY_CHECK_RET(lyb_write_string(opaq->prefix.ns, 0, 1, out, lybctx));
+
+    /* name */
+    LY_CHECK_RET(lyb_write_string(opaq->name, 0, 1, out, lybctx));
+
+    /* value prefixes */
+    LY_CHECK_RET(lyb_print_opaq_prefixes(out, opaq->val_prefs, lybctx));
+
+    /* format */
+    LY_CHECK_RET(lyb_write_number(opaq->format, 1, out, lybctx));
+
+    /* value */
+    LY_CHECK_RET(lyb_write_string(opaq->value, 0, 0, out, lybctx));
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Print anydata node.
+ *
+ * @param[in] anydata Node to print.
+ * @param[in] out Out structure.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_anydata(struct lyd_node_any *anydata, struct ly_out *out, struct lyd_lyb_ctx *lybctx)
+{
+    LY_ERR ret = LY_SUCCESS;
+    LYD_ANYDATA_VALUETYPE value_type;
+    int len;
+    char *buf = NULL;
+    const char *str;
+    struct ly_out *out2 = NULL;
+
+    if (anydata->value_type == LYD_ANYDATA_DATATREE) {
+        /* will be printed as a nested LYB data tree */
+        value_type = LYD_ANYDATA_LYB;
+    } else {
+        value_type = anydata->value_type;
+    }
+
+    /* first byte is type */
+    LY_CHECK_GOTO(ret = lyb_write(out, (uint8_t *)&value_type, sizeof value_type, lybctx), cleanup);
+
+    if (anydata->value_type == LYD_ANYDATA_DATATREE) {
+        /* print LYB data tree to memory */
+        LY_CHECK_GOTO(ret = ly_out_new_memory(&buf, 0, &out2), cleanup);
+        LY_CHECK_GOTO(ret = lyb_print_data(out2, anydata->value.tree, LYDP_WITHSIBLINGS), cleanup);
+
+        len = lyd_lyb_data_length(buf);
+        assert(len != -1);
+        str = buf;
+    } else if (anydata->value_type == LYD_ANYDATA_LYB) {
+        len = lyd_lyb_data_length(anydata->value.mem);
+        assert(len != -1);
+        str = anydata->value.mem;
+    } else {
+        len = strlen(anydata->value.str);
+        str = anydata->value.str;
+    }
+
+    /* followed by the content */
+    LY_CHECK_GOTO(ret = lyb_write_string(str, (size_t)len, 0, out, lybctx), cleanup);
+
+cleanup:
+    ly_out_free(out2, NULL, 1);
+    return ret;
+}
+
+/**
+ * @brief Print term node.
+ *
+ * @param[in] term Node to print.
+ * @param[in] out Out structure.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_term(struct lyd_node_term *term, struct ly_out *out, struct lyd_lyb_ctx *lybctx)
+{
+    LY_ERR ret;
+    int dynamic;
+    const char *str;
+
+    /* get value */
+    str = lyd_value2str(term, &dynamic);
+
+    /* print it */
+    ret = lyb_write_string(str, 0, 0, out, lybctx);
+
+    if (dynamic) {
+        free((char *)str);
+    }
+    return ret;
+}
+
+/**
+ * @brief Print YANG node metadata.
+ *
+ * @param[in] out Out structure.
+ * @param[in] node Data node whose metadata to print.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_metadata(struct ly_out *out, const struct lyd_node *node, struct lyd_lyb_ctx *lybctx)
+{
+    LY_ERR ret;
+    int dynamic;
+    uint8_t count = 0;
+    const struct lys_module *wd_mod = NULL;
+    struct lyd_meta *iter;
+    const char *str;
+
+    /* with-defaults */
+    if (node->schema->nodetype & LYD_NODE_TERM) {
+        if (((node->flags & LYD_DEFAULT) && (lybctx->options & (LYDP_WD_ALL_TAG | LYDP_WD_IMPL_TAG))) ||
+                ((lybctx->options & LYDP_WD_ALL_TAG) && ly_is_default(node))) {
+            /* we have implicit OR explicit default node, print attribute only if context include with-defaults schema */
+            wd_mod = ly_ctx_get_module_latest(node->schema->module->ctx, "ietf-netconf-with-defaults");
+        }
+    }
+
+    /* count metadata */
+    if (wd_mod) {
+        ++count;
+    }
+    for (iter = node->meta; iter; iter = iter->next) {
+        if (count == UINT8_MAX) {
+            LOGERR(lybctx->ctx, LY_EINT, "Maximum supported number of data node metadata is %u.", UINT8_MAX);
+            return LY_EINT;
+        }
+        ++count;
+    }
+
+    /* write number of metadata on 1 byte */
+    LY_CHECK_RET(lyb_write(out, &count, 1, lybctx));
+
+    if (wd_mod) {
+        /* write the "default" metadata */
+        LY_CHECK_RET(lyb_write_start_subtree(out, lybctx));
+        LY_CHECK_RET(lyb_print_model(out, wd_mod, lybctx));
+        LY_CHECK_RET(lyb_write_string("default", 0, 1, out, lybctx));
+        LY_CHECK_RET(lyb_write_string("true", 0, 0, out, lybctx));
+        LY_CHECK_RET(lyb_write_stop_subtree(out, lybctx));
+    }
+
+    /* write all the node metadata */
+    LY_LIST_FOR(node->meta, iter) {
+        /* each metadata is a subtree */
+        LY_CHECK_RET(lyb_write_start_subtree(out, lybctx));
+
+        /* model */
+        LY_CHECK_RET(lyb_print_model(out, iter->annotation->module, lybctx));
+
+        /* annotation name with length */
+        LY_CHECK_RET(lyb_write_string(iter->name, 0, 1, out, lybctx));
+
+        /* get the value */
+        str = lyd_meta2str(iter, &dynamic);
+
+        /* metadata value */
+        ret = lyb_write_string(str, 0, 0, out, lybctx);
+        if (dynamic) {
+            free((char *)str);
+        }
+        LY_CHECK_RET(ret);
+
+        /* finish metadata subtree */
+        LY_CHECK_RET(lyb_write_stop_subtree(out, lybctx));
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Print opaque node attributes.
+ *
+ * @param[in] out Out structure.
+ * @param[in] node Opaque node whose attributes to print.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_attributes(struct ly_out *out, const struct lyd_node_opaq *node, struct lyd_lyb_ctx *lybctx)
+{
+    uint8_t count = 0;
+    struct ly_attr *iter;
+
+    for (iter = node->attr; iter; iter = iter->next) {
+        if (count == UINT8_MAX) {
+            LOGERR(lybctx->ctx, LY_EINT, "Maximum supported number of data node attributes is %u.", UINT8_MAX);
+            return LY_EINT;
+        }
+        ++count;
+    }
+
+    /* write number of attributes on 1 byte */
+    LY_CHECK_RET(lyb_write(out, &count, 1, lybctx));
+
+    /* write all the attributes */
+    LY_LIST_FOR(node->attr, iter) {
+        /* each attribute is a subtree */
+        LY_CHECK_RET(lyb_write_start_subtree(out, lybctx));
+
+        /* prefix */
+        LY_CHECK_RET(lyb_write_string(iter->prefix.pref, 0, 1, out, lybctx));
+
+        /* namespace */
+        LY_CHECK_RET(lyb_write_string(iter->prefix.ns, 0, 1, out, lybctx));
+
+        /* name */
+        LY_CHECK_RET(lyb_write_string(iter->name, 0, 1, out, lybctx));
+
+        /* value prefixes */
+        LY_CHECK_RET(lyb_print_opaq_prefixes(out, iter->val_prefs, lybctx));
+
+        /* format */
+        LY_CHECK_RET(lyb_write_number(iter->format, 1, out, lybctx));
+
+        /* value */
+        LY_CHECK_RET(lyb_write_string(iter->value, 0, 0, out, lybctx));
+
+        /* finish attribute subtree */
+        LY_CHECK_RET(lyb_write_stop_subtree(out, lybctx));
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Print schema node hash.
+ *
+ * @param[in] out Out structure.
+ * @param[in] schema Schema node whose hash to print.
+ * @param[in,out] sibling_ht Cached hash table for these siblings, created if NULL.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_schema_hash(struct ly_out *out, struct lysc_node *schema, struct hash_table **sibling_ht, struct lyd_lyb_ctx *lybctx)
+{
+    LY_ARRAY_SIZE_TYPE u;
+    uint32_t i;
+    LYB_HASH hash;
+    struct lyd_lyb_sib_ht *sib_ht;
+    struct lysc_node *first_sibling;
+
+    if (!schema) {
+        /* opaque node, write empty hash */
+        hash = 0;
+        LY_CHECK_RET(lyb_write(out, &hash, sizeof hash, lybctx));
+        return LY_SUCCESS;
+    }
+
+    /* create whole sibling HT if not already created and saved */
+    if (!*sibling_ht) {
+        /* get first schema data sibling (or input/output) */
+        first_sibling = (struct lysc_node *)lys_getnext(NULL, lysc_data_parent(schema), schema->module->compiled, 0);
+        LY_ARRAY_FOR(lybctx->sib_hts, u) {
+            if (lybctx->sib_hts[u].first_sibling == first_sibling) {
+                /* we have already created a hash table for these siblings */
+                *sibling_ht = lybctx->sib_hts[u].ht;
+                break;
+            }
+        }
+
+        if (!*sibling_ht) {
+            /* we must create sibling hash table */
+            LY_CHECK_RET(lyb_hash_siblings(first_sibling, sibling_ht));
+
+            /* and save it */
+            LY_ARRAY_NEW_RET(lybctx->ctx, lybctx->sib_hts, sib_ht, LY_EMEM);
+
+            sib_ht->first_sibling = first_sibling;
+            sib_ht->ht = *sibling_ht;
+        }
+    }
+
+    /* get our hash */
+    LY_CHECK_RET(lyb_hash_find(*sibling_ht, schema, &hash));
+
+    /* write the hash */
+    LY_CHECK_RET(lyb_write(out, &hash, sizeof hash, lybctx));
+
+    if (hash & LYB_HASH_COLLISION_ID) {
+        /* no collision for this hash, we are done */
+        return LY_SUCCESS;
+    }
+
+    /* written hash was a collision, write also all the preceding hashes */
+    for (i = 0; !(hash & (LYB_HASH_COLLISION_ID >> i)); ++i);
+
+    for (; i; --i) {
+        hash = lyb_hash(schema, i - 1);
+        if (!hash) {
+            return LY_EINT;
+        }
+        assert(hash & (LYB_HASH_COLLISION_ID >> (i - 1)));
+
+        LY_CHECK_RET(lyb_write(out, &hash, sizeof hash, lybctx));
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Print data subtree.
+ *
+ * @param[in] out Out structure.
+ * @param[in] node Root node of the subtree to print.
+ * @param[in,out] sibling_ht Cached hash table for these data siblings, created if NULL.
+ * @param[in] lybctx LYB context.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyb_print_subtree(struct ly_out *out, const struct lyd_node *node, struct hash_table **sibling_ht, struct lyd_lyb_ctx *lybctx)
+{
+    struct hash_table *child_ht = NULL;
+
+    /* register a new subtree */
+    LY_CHECK_RET(lyb_write_start_subtree(out, lybctx));
+
+    /* write model info first */
+    if (!node->schema && !((struct lyd_node_opaq *)node)->parent) {
+        LY_CHECK_RET(lyb_print_model(out, NULL, lybctx));
+    } else if (node->schema && !lysc_data_parent(node->schema)) {
+        LY_CHECK_RET(lyb_print_model(out, node->schema->module, lybctx));
+    }
+
+    /* write schema hash */
+    LY_CHECK_RET(lyb_print_schema_hash(out, (struct lysc_node *)node->schema, sibling_ht, lybctx));
+
+    /* write any metadata/attributes */
+    if (node->schema) {
+        LY_CHECK_RET(lyb_print_metadata(out, node, lybctx));
+    } else {
+        LY_CHECK_RET(lyb_print_attributes(out, (struct lyd_node_opaq *)node, lybctx));
+    }
+
+    /* write node content */
+    if (!node->schema) {
+        LY_CHECK_RET(lyb_print_opaq((struct lyd_node_opaq *)node, out, lybctx));
+    } else if (node->schema->nodetype & LYD_NODE_INNER) {
+        /* nothing to write */
+    } else if (node->schema->nodetype & LYD_NODE_TERM) {
+        LY_CHECK_RET(lyb_print_term((struct lyd_node_term *)node, out, lybctx));
+    } else if (node->schema->nodetype & LYD_NODE_ANY) {
+        LY_CHECK_RET(lyb_print_anydata((struct lyd_node_any *)node, out, lybctx));
+    } else {
+        LOGINT_RET(lybctx->ctx);
+    }
+
+    /* recursively write all the descendants */
+    LY_LIST_FOR(lyd_node_children(node, 0), node) {
+        LY_CHECK_RET(lyb_print_subtree(out, node, &child_ht, lybctx));
+    }
+
+    /* finish this subtree */
+    LY_CHECK_RET(lyb_write_stop_subtree(out, lybctx));
+
+    return LY_SUCCESS;
+}
+
+LY_ERR
+lyb_print_data(struct ly_out *out, const struct lyd_node *root, int options)
+{
+    LY_ERR ret = LY_SUCCESS;
+    uint8_t zero = 0;
+    LY_ARRAY_SIZE_TYPE u;
+    struct hash_table *top_sibling_ht = NULL;
+    const struct lys_module *prev_mod = NULL;
+    struct lyd_lyb_ctx lybctx = {0};
+
+    lybctx.options = options;
+    if (root) {
+        lybctx.ctx = LYD_NODE_CTX(root);
+
+        if (root->schema && lysc_data_parent(root->schema)) {
+            LOGERR(lybctx.ctx, LY_EINVAL, "LYB printer supports only printing top-level nodes.");
+            return LY_EINVAL;
+        }
+    }
+
+    /* LYB magic number */
+    LY_CHECK_GOTO(ret = lyb_print_magic_number(out, &lybctx), cleanup);
+
+    /* LYB header */
+    LY_CHECK_GOTO(ret = lyb_print_header(out, &lybctx), cleanup);
+
+    /* all used models */
+    LY_CHECK_GOTO(ret = lyb_print_data_models(out, root, &lybctx), cleanup);
+
+    LY_LIST_FOR(root, root) {
+        /* do not reuse sibling hash tables from different modules */
+        if (!root->schema || (root->schema->module != prev_mod)) {
+            top_sibling_ht = NULL;
+            prev_mod = root->schema ? root->schema->module : NULL;
+        }
+
+        LY_CHECK_GOTO(ret = lyb_print_subtree(out, root, &top_sibling_ht, &lybctx), cleanup);
+
+        if (!(options & LYDP_WITHSIBLINGS)) {
+            break;
+        }
+    }
+
+    /* ending zero byte */
+    LY_CHECK_GOTO(ret = lyb_write(out, &zero, sizeof zero, &lybctx), cleanup);
+
+cleanup:
+    LY_ARRAY_FREE(lybctx.subtrees);
+    LY_ARRAY_FOR(lybctx.sib_hts, u) {
+        lyht_free(lybctx.sib_hts[u].ht);
+    }
+    LY_ARRAY_FREE(lybctx.sib_hts);
+
+    return ret;
+}