You can read the announcement in PDF file.
It is possible to use some symbols in place of variable signs, numbers and (or) letters in cases when such signs, numbers and (or) letters uniquely identify variables parameters of products that do not affect to the mandatory requirements of technical regulations that have been confirmed by certification or declaration conformity assessment procedures.
The specified influence (or absence of influence) is determined by the certification expert basing on the technical documentation analysis that has to be stored at technical file. The technical report shall contain the unambiguous conclusion that the variable symbols do not affect to the mandatory requirements of technical regulations.
In case of using some variable symbols for the product identification for the conformity assessment purposes the applicant is responsible for this coding. To avoid any misleading of consumers there should be interpretation of the symbol used at the certificate of conformity.