To save myself from writing a more detailed follow-up, I’d like to direct all those who were interested in this subject to read a thread I started on Swordforum*. Pay special attention to Mr. Tom Leoni’s posts where he addresses the issue.
For those without the patience, I’ll simply summarize that the word phrase ala traversa, in it’s various forms of spelling should be read as an adverb with a meaning similar to “obliquely”. The phrase ala coverta can be read as “to the cover” and the words are not used synonymously.
* SwordForum unfortunately is no longer available.