Help With Explanation of Baptism Record

Hello, I came accross a Baptismo Record while doing research and I don't believe I've ever seen this.

The record states in parenthesis "(a quien baptizo en caso de necesidad Don Antonio Marmolejo)." I know for a fact that this person is not a member of the clergy from researching thousands of records from this parish. Don Antonio Marmolejo is married and has children.

Was this a common practice? Allowing someone other than a priest to baptize children?

Here is the link: No. 305 left page

https://www.familysearch.org/ark:/61903/3:1:9392-2GSD-5C?i=341&wc=3J6H-HZS%3A171935301%2C171935302%2C171935303&cc=1874591

Thanks
Ruben R