Adopted by a clan called 'The Cider-Riders' , the phrase has spread to mainstream use by the students of KEGs, which is a college in a town somewhere near Coventry.
'Remember to always check for BIR prior to bitching.'
Cider-Rider-2: "Shit check for B.I.R!"
*looks behind and all around*
Cider-Rider-1:*whispers* "oooooohmygod shes sitting behind us....."