PAL

Ptolemaeus Arabus et Latinus

_ (the underscore) is the placeholder for exactly one character.
% (the percent sign) is the placeholder for no, one or more than one character.
%% (two percent signs) is the placeholder for no, one or more than one character, but not for blank space (so that a search ends at word boundaries).

At the beginning and at the end, these placeholders are superfluous.

Work B.1.9

Pseudo-Ptolemy
Centiloquium (tr. Giovanni Pontano)

This translation is part of Giovanni Pontano’s Liber commentationum in Centum sententiis Ptolemaei. See C.3.16.