https://praguepig.com/2019/07/ceska-posta-denies-using-secret-u86-code-to-identify-customers-whose-balik-do-ruky-parcel-delivery-to-hand-deliveries-get-sent-to-nearest-post-office-rather-than-to-their-home-blames-1/
Ceska posta denies using secret "U86" code to identify customers whose "Balik Do ruky" ("Parcel Delivery to Hand") deliveries get sent to nearest post office rather than to their home; blames 1,100+ staff shortage for problems (Aktualne.cz) [Social Media Post]