Which investigator-restricted cards must be included in a deck, and can they be removed?

Question

Accepted Answer

Check the deckbuilding requirements on the back of the investigator card. Cards that must be included, such as signature cards, cannot be removed voluntarily, and cards granted during a campaign also cannot be removed once granted.

Arkham Horror: The Card Game (Revised Core Set)

Which investigator-restricted cards must be included in a deck, and can they be removed?