Alias definition:
ALIASES += WIP{1}="<div style='border:1px dotted magenta'>\1</div>"

Alias usage:
\WIP{Die not, spare life}

Result:
{Die not, spare life}    //no frame! only the brackets left from the command

In case if comma is escaped, alias works fine:
\WIP{Die not\, spare life}
results in:
Die not, spare life      //text in a frame - as expected

But I don't want to escape commas every time, and according to Doxygen documentation "13.2 Aliases with arguments" it is only required for aliases with more than one argument.