"Alt Gr
+ ,"
followed by "c"
will produce: ç
This actually makes sense as stated by yanglifu9's in a greatly underrated post here:
"It is natural that
'
- c
will produce ć
since on the layout the key '
is shown as acute accent ( ´
)."See also:
http://dry.sailingissues.com/us-international-keyboard-layout.html