[item] does not work for some items

[daniel-skopek]

Items like signed writtable book or custom player head (for example from /phead <player_name>) are not showed in [item] - nothing is replaced.

[Elikill58]

From which plugin is "phead" ?

[daniel-skopek]

Head Database: https://www.spigotmc.org/resources/head-database.14280/

But players reported custom heads not working as well from plugin Minepacks (for example): https://www.spigotmc.org/resources/minepacks-backpack-plugin-mc-1-7-1-21.19286/