How flexible is "Teacher Recommenders"?

Applying to College
1

I’ve requested four letters of recommendation: three from teachers, and one from a computer science professor I worked with as a research intern over the summer. Each college I’m applying to has different policies, like 2 teacher recs and 2 other recs, or 3 and 1 or 1 and 0, etc. So I tailor my recommenders accordingly.

However, a few colleges I’m applying to have 3 Teacher Recommendations but 0 Other Recommendations. Would it be okay to have my professor’s rec as one of the “Teacher Recs”? I really believe he can give unique insight that’ll strengthen my application.

Another thing I’ve been reading about on CC is mailing it in, so if that’s better I might just do that.

2

Teacher recommendations are typically reserved for teachers who have had you in an academic class. The professor you did research will would fall under the category of a supplemental recommendation.