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.

lunar sphere ‘lunar sphere’

English

References: Alm. Toomer: 36. – PH Hamm: I.9:1, 51:3
Translation of:
Greek: σεληνιακὴ σφαίρα [Alm. Heiberg: I.1, 5:24. – PH Heiberg: I.9:1, 80:28]