This previously unidentified fragment belongs to a commentary on the lexical series Aa. It comments in all likelihood on a section concerned with the readings of the sign lá, a section that is unfortunately not preserved in the extant manuscripts of Aa.1
The reverse of the fragment is anepigraphic, which probably means that the obverse belongs to the upper part of the tablet. Several other tablets from the 81-11-3 consignment contain commentaries on the series Aa, albeit most of them comment on Aa II. The present fragment could conceivably belong to any of them. For a list, see here.