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.

οἰκοδεσπότης ‘a planet that hosts another planet in its home’

Greek. – Grammar: noun.

References: Pontano: p. 328
Translated into:
Latin: hospitator (planeta) [Pontano: XXXIVc. 14; LXXXc. 3]