TITLE: Parahoric Group Scheme
QUESTION [9 upvotes]: I am looking for the definition of a parahoric group scheme in the sense of Bruhat and Tits? I couldn't find a reference for that? at least a "clear" reference!
thanks

REPLY [4 votes]: What George McNinch has written is most helpful, but maybe I can point out an obstacle to locating the sort of precise reference you ask for.    The most relevant work of Bruhat-Tits, apart from surveys such as the one by Tits in English which George refers to, is found online at numdam.org, starting with their IHES papers I and II.   In each paper there are many separate occurrences of the terms schema and sous-groupes parahoriques but apparently no explicit formulation of the definition you want.  Another paper by them here may also be useful.    Their style however is quite formal, as you realize.   (I guess it's clear that the artificial term parahorique combines the notions of parabolic subgroup and Iwahori subgroup in the case of local fields.)