RESOLVED: appendPar() doesn't work for underscore

I’m using Chop channel names as a source. If the channel name begins with a lowercase, that’s not a problem, it will convert it to uppercase, but if the channel contains an underscore _ it will give the error:

First argument must be parameter name, and begin with uppercase letter followed by lowercase letters and numbers only.

According to the page class wiki, there should be no problem:

Thanks for the report.
We are currently investigating how to expand our naming requirements throughout the software in general.
Currently however, custom names still have those restrictions.
We will update the docs to reflect that.