passport

(noun) any authorization to pass or go somewhere. Synonyms: pass. Example: "The pass to visit had a strict time limit."

(noun) a document issued by a country to a citizen allowing that person to travel abroad and re-enter the home country.

(noun) any quality or characteristic that gains a person a favorable reception or acceptance or admission. Synonyms: recommendation. Examples: "Her pleasant personality is already a recommendation." "His wealth was not a passport into the exclusive circles of society."