Many spreadsheet functions (e.g., SUMIF ) allow using "search criterion" (a special pseudotype defined in ODF ), which has some not obvious rules. The current help only tangentially mentions one aspect from there, namely that the text is attempted to be converted to number before being used as a regular expression.
The dedicated description of "search criterion" is needed, and added to the functions using it.
Moving to NEW
Olivier Hallot committed a patch related to this issue.
It has been pushed to "master":
tdf#131995 Be precise with Criterion in Calc