old school tie

noun

1. a necktie striped in the colors of a specific English public school, especially as worn by a graduate to indicate his educational background.
2. an alumnus of an English public school.
3. the clannishness and conservative manners, dress, and attitudes associated with students and graduates of the English public schools.
4. snobbishness, clannishness, or extreme conservatism.

noun

1. British a distinctive tie that indicates which school the wearer attended
2. the attitudes, loyalties, values, etc, associated with British public schools