Merge pull request #512 from Laura-O/clock-pieces

Clarify similar Clock pieces, fixes #409

wca-guidelines.md

@@ -74,7 +74,7 @@ To be more informative, each Guideline is classified using one of the following
 - 3h2++) [CLARIFICATION] "Stickerless" puzzles that significantly differ from most mass-produced "stickerless" puzzles are only permitted at the discretion of the WCA Delegate.
 - 3j+) [REMINDER] In the past, engraved/embossed parts have been permitted. This is no longer permitted.
 - 3j++) [CLARIFICATION] On Clock, pins must not be distinguishable from any other pin of the same side.
-- 3j2+) [CLARIFICATION] On Clock, all eighteen inner clock faces are considered similar pieces.
+- 3j2+) [CLARIFICATION] On Clock, the nine inner clock faces on one side are considered similar pieces.
 - 3l+) [ADDITION] Logos may feature any reasonable design that does not give a conspicuous advantage (e.g. encoding information that could be used to cheat), and leave the colored part clearly recognizable. Unconventional logos are only permitted at the discretion of the WCA Delegate.