21. No later than the last day of the reference period in effect, a representative may, in accordance with section 20, submit an application for recognition of a training activity in which he took part and which has not already been recognized. The recognition decision rendered pursuant to such an application is valid only for the representative in question. In addition to the elements mentioned in section 20, the representative must provide a voucher attesting that he attended the activity or a certificate of exam or test results, as the case may be.