Mind Mask

(Secrets of Sarlona, page 117, DnD 3.5)

[Psionic]

Your mind conceals some of your traits.

Benefit

Effects that detect alignment reveal that you are neutral, and "
detect magic":/spells/players-handbook-v35--6/detect-magic--2489/ and
detect psionics reveal you to be nonmagical and nonpsionic, regardless of your true nature. You also get a +1 bonus on saving throws against mind-affecting spells, power, and abilities. If you wish, you can suppress the benefit of this feat to reveal your actual characteristics and forgo the save bonus.

Special

This feat does not mask the aura of effects you create or items in you possession, including ongoing spells and powers, as well as imbedded magic or psionic items.

Normal

A creature's aura reveals its alignment and psionic nature.