Before 1989, this grammar point was written as -읍니다 after final consonants ㅆ and ㅄ. For example:
This usage of -읍니다 can still be seen in the writings of older people or to give a piece of text the vibe that a person who learned Korean spelling before 1989 is writing it. In modern usage, this form can sometimes be used humorously even after consonants that usually wouldn't take -읍니다. For example: