Chess variants and the UCI protocol

[ilari]

I was wondering how FRC support is implemented in the UCI protocol. Is there a specific option/command that the engine can send to tell that it supports FRC? And which FEN format should I use, X-FEN or Shredder FEN?

How about Capablanca or Gothic chess, is there even an unofficial version of UCI that supports these?

[hgm]

option name UCI_Chess960 type check default false

I think UCI prescribes Shredder FEN.

The only Capablanca-capable UCI engines that I know are those of Mathias. (Although I always use them as WB, which they also speak.) If I look at the options that they print through Polyglot GUI, I see:

UCI_Capablanca
UCI_8x8Capablanca
UCI_Caparandom
UCI_Gothic
UCI_Bird

As I suppose that these options are understood by ChessGUI, they should be considered the unofficial UCI standard, for lack of competition.

Although in general I try to stay away from UCI, this might be a good opportunity to also define the standard options

UCI_Losers
UCI_Giveaway
UCI_Suicide
UCI_Atomic
UCI_Shatranj
UCI_Janus
UCI_Seirawan
UCI_Knightmate

[hgm]

Oh yes, and of course

UCI_Crazyhouse
UCI_Bughouse

[ilari]

Thanks a lot, that was just what I needed.