Docs: Improvements and corrections to documentation relating to metadata.

See #63166

git-svn-id: https://develop.svn.wordpress.org/trunk@60264 602fd350-edb4-49c9-b593-d223f7449a82

Author: johnbillion

src/wp-includes/comment.php

@@ -446,6 +446,8 @@ function get_comment_count( $post_id = 0 ) {
 /**
  * Adds meta data field to a comment.
  *
+ * For historical reasons both the meta key and the meta value are expected to be "slashed" (slashes escaped) on input.
+ *
  * @since 2.9.0
  *
  * @link https://developer.wordpress.org/reference/functions/add_comment_meta/
@@ -474,6 +476,8 @@ function add_comment_meta( $comment_id, $meta_key, $meta_value, $unique = false
  * value, will keep from removing duplicate metadata with the same key. It also
  * allows removing all metadata matching key, if needed.
  *
+ * For historical reasons both the meta key and the meta value are expected to be "slashed" (slashes escaped) on input.
+ *
  * @since 2.9.0
  *
  * @link https://developer.wordpress.org/reference/functions/delete_comment_meta/
@@ -540,6 +544,8 @@ function wp_lazyload_comment_meta( array $comment_ids ) {
  *
  * If the meta field for the comment does not exist, it will be added.
  *
+ * For historical reasons both the meta key and the meta value are expected to be "slashed" (slashes escaped) on input.
+ *
  * @since 2.9.0
  *
  * @link https://developer.wordpress.org/reference/functions/update_comment_meta/