Hello @senna0202,
These postage stamps were issued in accordance with the 25 Sept., 1915 decree of the Council of Ministers. This issue is separate from other banknote issues under the Imperial Russian government.
These stamps were created for two reasons: to supply the economy with small change due to a coin shortage and to commemorate the 300th year of Reign of the House of Romanov. So, to answer your question, I believe that this emergency postage stamp series should be its own series titled “300th year of the House of Romanov reign emergency change stamps”.
Best,
Daniel