"Guide to Etiquette,1927, Chapter 8, Paragraph 2"

When releasing flatulence with a recognizable odor, from an uncontrollable pre defacate state, in a crowded area such as an elevator a small room or a dinner party, the following etiquette applies;

Do not forcefully expel the gas as this may cause a loud report whereby you will surely be known as the offending party and possibly asked to leave the area.

Go on about your routine as if nothing had happened, masking your awareness of the noxious odor, even if this odor brings you to a tear like state.

As a last resort glare offendingly at another party as for them to take the blame, preferably a gentleman of less than diligent looks and or other slovenly individuals.