Metadata (postmeta) (category)
| delete_post_meta_by_key() | Deletes everything from post meta matching the given meta key. |
| wp_generate_attachment_metadata() | Generate post thumbnail attachment meta data. |
| wp_get_attachment_metadata() | Retrieve attachment meta field for attachment ID. |
| wp_maybe_generate_attachment_metadata() | Maybe attempts to generate attachment metadata, if missing. |
| wp_read_audio_metadata() | Retrieve metadata from a audio file's ID3 tags |
| wp_update_attachment_metadata() | Update metadata for an attachment. |