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.
Dijuro Sensei
Your non-Fortification Holdings enter play for 1 more Gold. Each Province you assigned a Personality to defend or with a Cavalry unit attacking it has +1 strength for each Fortification attached to it, and has a maximum strength equal to its printed strength +4.
Does Dijuro provide a +4 bonus to province strength, in addition to other bonuses provided by other fortifications; or does he cap the maximum province strength at +4 regardless of effects of other fortifications?
Dijuro Sensei
Your non-Fortification Holdings enter play for 1 more Gold. Each Province you assigned a Personality to defend or with a Cavalry unit attacking it has +1 strength for each Fortification attached to it, and has a maximum strength equal to its printed strength +4.
Does Dijuro provide a +4 bonus to province strength, in addition to other bonuses provided by other fortifications; or does he cap the maximum province strength at +4 regardless of effects of other fortifications?
It will cap the maximum strength at printed + 4, including all effects.