I know that here in my district a gifted child has to be seen by a teacher endorsed with gifted certification at least once a day...or in some circumstances less and then that person consults with the regular teacher. So what they did was say at every grade level you need teachers endorsed gifted and then they cluster the identified gifted kids in that teachers class...if the kids rotate classes (at one elementary school they do that starting in 4th grade) just one teacher on the team has to be.
Well once you get that number of gifted endorsed teachers in one school (at least 6 in a k-5 school). You started having a staff who have a basic understanding about gifted and start nominating those they come into contact with and start helping with differentiating ideas for other teachers and become resources and suggest...hey nominate that child for gifted testing.
I don't think nominating for gifted is top of the teachers priority list and it was a teacher who nominated my older yet I nominated my younger son...so 50/50.