The "Full Defense" Interrupt Action allows a character to decrease their Initiative Score by 10, and the add their Willpower to their defense rolls for the remainder of the Combat Turn. However, the section of the core rulebook describing this action is unclear on whether it may be performed more than once in the same Combat Turn. The relevant section of the rule is
This bonus is also cumulative with other Interrupt Actions.
It is unclear whether:
The word "other" refers to Interrupt Actions that are not Full Defense (so any of the others, such as Block, Parry, etc.). Therefore, a character is limited to one Full Defense action per Combat Turn.
The word "other" simply refers to Interrupt Actions that are not this specific action, which would allow for other Full Defense actions to be performed and stack their bonuses.
Is there another section of rules clarifying this, or is this just an unclear area that has to be adjudicated by the GM?