[#101] $ZC -> $ZCH
This is not a problem in the latest version of YottaDB, but is a problem in r134 and earlier due to them lacking the code from GT.M V6.3013 which relaxed the lookup requirements for $Z* characters.
See YottaDB/DB/YDB#925 (closed) for more information. We opted to keep the relaxed parsing from GT.M, so currently $ZC is accepted.