I noticed today that some of my macros were breaking in an odd way, and it seems to correspond to the use of numerals as parameter names. For instance:
Above, you can see that that the text of parameter “1” is being substituted in the “b” slot if “b” is not defined in the macrocall—as if it’s ignoring the parameter name and reverting to positional handling.
But this doesn’t happen if I use a letter rather than a numeral:
This seems to be a bug in both 5.3.0 and the current 5.3.1 prerelease.