Used to parse special syntax that can be used in the passives list to specify the item that grants the passive.
The passives list may contain elements of the format Passive name @ Item name to specify that the passive is granted by that item.
Results are passed on to Template:Infobox creature/passives query for further processing.
Example:
{{Infobox creature/passives parser | Ambusher (+1) @ Scale Mail +2 }}
Gain +1 to initiative rolls.