Blahfuckingblah. 
Fact is: some absurd and/or creative banners are "purged", some not. Makes no sense. 
And obviously the purgatory immersion fetish folks  don't give a fuck about game realism otherwise - and have no clue about how colorful and creative and obscene imagery (or heraldry) in medieval times actually was. 
For ATTS, this might be a nice replacement (all images from medieval sources): 
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login or full image incl. shooter here: 
http://d.pr/i/yhLSfor the "dear admin in charge of banners" this good medieval practice might be recommended: 
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logininside the mind of cav players: 
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loginand my general thoughts about the banner matter: 
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