"If a previous conviction is charged under Sub-Section (7) of Section 211 and the accused does not admit to it, the Judge may, after convicting the accused under Section 229 or Section 235, take evidence regarding the alleged prior conviction and record a finding. However, such a charge shall not be read out, nor shall the accused be asked to plead to it, nor shall the prosecution refer to it in any evidence unless and until the accused has been convicted under Section 229 or Section 235."