Some secret identities:

• The Scarlet Pimpernel: Sir Percy Blakeney
• Zorro: Don Diego De La Vega
• The Lone Ranger: John Reid
• The Phantom: Kit Walker
• Captain Marvel: Billy Batson

It’s been pointed out that Superman pretends to be Clark Kent, but Peter Parker pretends to be Spider-Man. If you have two identities, either one can be “secret.”