# Parity $P$ symmetry restored by 1 in the $1 \oplus \bar{5} \oplus 10$?

In Lie Algebras in Particle Physics 2ed - From Isospin to Unified Theories (Georgi, 1999) p.283

Georgi wrote:

When we include the $$1$$ in the $$\rm SU(5)$$ Unified Theory model, we get the 16 $$1 \oplus \bar{5} \oplus 10,$$ which we can restore the Parity $$P$$ symmetry lost in $$\rm SU(5)$$ Unified Theory model.

questions

• why is the Parity P symmetry lost in $$\rm SU(5)$$ Unified Theory model? I meant P is lost in weak interactions in general.

• why is the Parity P symmetry restored in the 16 as $$1 \oplus \bar{5} \oplus 10$$?

I am confused.