Your suggestion of the potential of unprintables was very astute- I removed the line and carefuly re-typed it. Same warning.
I noticed there were 2 constants defined. I moved the 2nd to the top , and now THAT one throws the warning , but the other is fine. So whichever is first throws a warning!
This makes me wonder- the author doesn't declare:
use constant;
above these pragmas. maybe that would fix this? I don't see that in the Metacpan but perhaps they're incomplete examples?
APPRECIATE all the kind advice guys- I'll wait for the admin to get my module updated and pray for better results :)
