Their IDENTITY is yet unknown.
Money Heist Season 1, Episode 12
He wants his own IDENTITY.
Breaking Bad Season 2, Episode 4
A captive knight has
a right to know his captor's IDENTITY.
Game of Thrones Season 2, Episode 8
They've confirmed their IDENTITY, Colonel.
Money Heist Season 3, Episode 7
...suffer from an external locus
of IDENTITY.
The Big Bang Theory Season 2, Episode 15