A "mere presence" provision in a good conduct rule provides sanctions for a student who is not in possession of or consuming alcohol or an illegal substance, but who is present where the student knows that others are unlawfully doing so. To be upheld as valid, mere presence language must provide a student with a reasonable opportunity to leave the presence of the alcohol or illegal substance without fear of sanctions. In the absence of such language, the school must give a student an opportunity to demonstrate that s/he took advantage of the first reasonable opportunity to leave the presence of the alcohol or illegal substance. In re Oelmann, 18 D.o.E. App. Dec. 288 (2000); In re Lureman, 18 D.o.E. App. Dec. 310 (2000).