In one of the footnotes in Popma's book, we read:
Vocabulum hocce in genere neutro h. l. esse positum, testatur Erythraeus in Ind. Virgil. fol. 41. fac. 2. col b.
I could not find Erythraeu's book itself to see if "h. l" occurs there also, or this "h. l" is related to the citation (but as the full citation comes later, it seem quite improbable).
Edit : in the following footnote we find also "h. e", that's too I could not decipher, but they might be related.