From LSWiki
[Spell :] Protection from Evil
[Level :] One
[Reversible :] Yes
[Sphere :] Protection
[Components :] None
[Usage :] cast protection from evil [-] [on <target>]
[Effect :] When protection from evil is cast an aura of holy
holy energy is summoned to protect the target
from any attackers that are aligned with the
forces of evil. Maintaining this aura is
somewhat draining on the spirit however. If the
reverse is cast the aura summoned will protect
the target from those that are good aligned.
If a target is not supplied it defaults to the
caster.