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, 31 March 2014
In regards to this post: viewtopic.php?f=59&t=107515
Bayushi Mamoru advises that "Home doesn't work in other battlefields, only if the card is at it controller's Home."
However, in regards to the Home keyword from Page 22 of the "Ivory Rules Reference Mar 13 2014.rtf" Home (keyword): An ability with the Home keyword may be used during battle even if the card it is on is not at the current battlefield.
I just want to be sure since for me when I read that, that tells me that if the card is at the current battlefield OR any other location that is not the current battlefield, then it is legal to play that action. If that is not the case, then can we pretty please have that re-worded to be clearer that the card MUST be at Home, not just at anywhere else other than the current battlefield as currently that wording is quite ambiguous.
Thank you.
A player, 31 March 2014
The question you mention is precisely because there's an erratum in the Reference Rules, so someone pointed out the contradiction between the Advanced Rules and the Reference Rules. Mistakes were made, now we're fixing them. Eventually the RR file will be updated with the correction.
Just to put it clear, the Reference Rules document has a mistake in the "Home (keyword)" section as of 31st March 2014 that will be fixed in future versions of the document. In the meantime please use the paragraph as described in the Advanced Rulebook.