Old school tie and Old boy network

Old school tie noun - Necktie indicating the school the wearer attended.

Old boy network and old school tie are semantically related. In some cases you can use "Old boy network" instead a noun phrase "Old school tie".

Old boy network noun - An exclusive informal network linking members of a social class or profession or organization in order to provide connections and information and favors (especially in business or politics).

Old school tie and old boy network are semantically related. You can use "Old school tie" instead a noun phrase "Old boy network".