I just noticed your comment about the 1F and looked closer. So this may be something that needs to be reviewed more carefully. This is also now used in PGstringevaluators.pl and parserCheckboxList.pl as well.
WeBWorK Problems
issue with contextArbitraryString
This forum has a limit to the number of forum postings you can make in a given time period - this is currently set at 5 posting(s) in 1 day