If he comes to say after his prayer, even according to the order of Yom Kippur he can say) This implies that in the midst of prayer, one should not. Now, regarding the current custom during fast days on Mondays and Thursdays, where people lengthen the Pesukei D'rachamim (verses of mercy) and Slichot (penitential prayers) within the Berachah of Selach Lanu (Forgive us), one might suggest that the community is different. This is akin to what we say in Berachot 34a, that an individual should not make personal requests in the first or last three blessings of the Shemoneh Esrei (silent prayer). Yet, we see the custom of saying Krovetz (liturgical additions) within the first three blessings during public prayer. It must be, therefore, that public prayer is different.

Horned It does not seem to him that Makrin (spelled with a yud) denotes a single horn any more than Makrin (spelled without a yud).