• A association or union
• B builder, rebuilder or equipment supplier
• D dealer
• E enthusiast(s)
• G general bus-related information
• H museum or heritage site
• M models and paper buses
• N newspapers books or magazines
• O operator
• P tickets, timetables and publicity
• R bus conversions, RVs, house buses
• S school buses
• T trolleys, trams and streetcars
• U newsgroup, bulletin board or mailing list
• W webring
• X miscellaneous