There are no "transcripts" for elementary.
There is no "standard practice."
I know it blows your mind; I felt the same way when I administered an umbrella school for homeschoolers, and requested cumulative records from dozens of public and private school.
It's most common for there to be photocopies of the children's report cards.
Bob Jones University Press (BJUP) has an "Elementary Academic Record
," which is similar to a transcript, but it isn't. Transcripts are high school level--at least, that's what most professional educators will say, and I think it's important for us homeschoolers to use the same vocabulary. :-)