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.

sphere ‘sphere’

English

References: PH Hamm: I.2:4, 46:8. – PH Morelon: I.2:4, 16:34
Translation of:
Greek: σφαῖρα [PH Heiberg: I.2:4, 72:25]
Arabic: كرة [PH Morelon: I.2:4, 17:19]