Polands Special Prefixes :

For commemorating the 90th Anniversary of their Independence, Poland is using many interesting prefixes like :

SP1918PR, HF1918PR, SO1918PR, SQ1918PR, SN1918PR, SO90PR, SN90PR, SQ90PR, HF90PR, SP90PR, etc.,.

Try working as many as you can, There may be some special award for working these special calls.

Source : VU2UR, OM ARASUJI