*holds hands up* ok guilty!but i did try and answer it a bit lol.
old school generally refers indeed as blythe says mainly to the leather boys although not always.
old school was much more about ettiquette, protocol and whilst all the emblems,ssc,rack do this dont do that limits and more often than not safewords were occasionally applied more often than not they were scorned upon it just wasnt expected on either Dom/me or sub side, this was just before ''old shool'' actually became old school lol. discipline played a much stronger part than it does now and in a totally different way, discipline more in the original sense of the term..not just a spanking (that sometimes turns into a bit of kinky fun) a stern look or a bit of a lecture it was real discipline of a kind that you avoided at all costs! kind of victorian in a way.

dress in anywhere related was usually a must not an option,and at home, it wasnt really considered a fetish or a bit of fun or roleplay it genuinely was a way of life ..hence the turn of phrase lifestyle, yep you can all jump on the bandwagon and exclaim how we ''live the lifestyle'' and to a degree you'd be right but the way we live and view the lifestyle would simply have been loosely based roleplay to the majority of the genuine oldschoolers..as i said in my first post we would mostly be considered a disgrace!
i used to go to a few bars and clubs in a specific area and made quite a few friends and acquaintences who never ever once actually told me what they were/did (other than one and thats a different story lol) although i didnt realise it at the time there were many D/s couples both straight and gay who most people thought were weird (i was fascinated and loved it lol) and they were and behaved what they were without any selfconciousness or care what anyone else thought, and it was natural simply a party of who and what they are they didnt stop and think about it or need to ''discuss everything'' the kind of things that we would consider exhibitionism and get a kick out of and feel brave etc they didnt...it wasnt contrived it was who and what they were and what they believed in..nothing to do with being gentlemanly etc im not saying they wernt or that they were it was just them.
i cant really explain it you would have to have been there and im sure some here were although at the same time im sure that the majority of ''old schoolers'' wouldnt deem bdsm sites worth their time.