A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 7 February 2013
According to the ruling of Incense Mill "Incense Mill will not negate effects that say an ability may not be used. It only will negate effects that explicitly prevent performing, including traits like those on Akodo Hotaka, Chiisai or Raido no Oni."
In regards to Chiisai, does this allow him to just take political/iaijutsu actions, since they are explicitly listed as "may not perform", or does it also allow him to perform the rulebook ability to attach items?
Relevant Chiisai text "Will not attach Items. May not perform Iaijutsu or Political actions. Melee Attacks may not target Chiisai's Followers." Incense Mill "Battle/Open: Target a Personality: Negate all current Force penalties on him. Negate any cards' effects that say he may not perform actions (this turn)."
A player, 7 February 2013
According to the ruling of Incense Mill "Incense Mill will not negate effects that say an ability may not be used. It only will negate effects that explicitly prevent performing, including traits like those on Akodo Hotaka, Chiisai or Raido no Oni."
In regards to Chiisai, does this allow him to just take political/iaijutsu actions, since they are explicitly listed as "may not perform", or does it also allow him to perform the rulebook ability to attach items?
Relevant Chiisai text "Will not attach Items. May not perform Iaijutsu or Political actions. Melee Attacks may not target Chiisai's Followers." Incense Mill "Battle/Open: Target a Personality: Negate all current Force penalties on him. Negate any cards' effects that say he may not perform actions (this turn)."
The restriction on attaching Items is not restricting him from performing an action, but restricting him the choice of attaching a specific card type . Chiisai is still be able to perform the Equip action, for example. His controller just can't choose to target an Item when Chiisai performs it.
It is the same kind of restriction that forbids a non-shugenja from attaching Spells. Incense Mill wouldn't remove this choice restriction either.