What payment purpose must be indicated when transferring funds?

2018-01-22 00:00:00:

When transferring via Internet banking, you must specify such a purpose of payment as "Private transfer" or "Refund". You cannot indicate the application number, the word "Exchange", various names of cryptocurrencies in the comments to the payment, as this may arouse the bank's suspicions and lead to the blocking of both our and your accounts and bank cards.