GTK Simple IM Context Compose Sequence restrictions ?

["Suzuki K P" <suzuki kp gmail com>]

Hi

Is there a restriction on the characters that can be used for the
Compose sequence table for GTK IM Context ?

I tried using GDK_semicolon and GDK_Alt_L  for appending a few compose
sequences for the im-cedilla input method.

I could find that the modifier keys  (GDK_Alt_*, GDK_Shift_*, etc )
are eliminated from the compose sequences. I tried deleting the
GDK_Alt_L from the list. But it didn't help with the table entries.

So my question is :

I s there a limit/restriction on the symbol sets that can not be used
in compose table ?


Thanks

Suzuki