13. If a trade mark contains¬-(a) any part not separately registered as a trade mark in the name of the proprietor, or for the separate registration of which no application has been made, or(b) any matter common to the trade, or otherwise of a non-distinctive character,the tribunal, in deciding whether the trade mark shall be entered or shall remain on the register, may require, as a condition of its being on the register, that the proprietor shall either disclaim any right to the exclusive use of such part or of all or any portion of such matter, as the case may be, to the exclusive use of which the tribunal holds him not to be entitled, or make such other disclaimer as the tribunal may consider necessary for the purpose of defining the rights of the proprietor under the registration: Provided that no disclaimer shall affect any rights of the proprietor of a trade mark except such as arise out of the registration of the trade mark in respect of which the disclaimer is made.