The identical mark might be used by a legal entity for similar goods and services. You should remember that in Russia the right for a trademark appears only upon official registration. Or there might be firms with the name partially or totally identical to your mark. If the firm had been established before the mark was registered, the firm retains the right to use the its name in respect of registered activities and may only concede to alter the name subject to an agreement.
So, before filing the application it makes sense to identify such marks and think of ways to protect your rights for the mark in Russia.
Among the sources used for the service are data bases of the regional Registration Boards and reference books, nnewspapers and magazines, advertising materials, science and technology data bases, etc.