File1:record :=: file2:record

I have some code that seems to be adding content to one file from another using the code below. But I can’t find any reference to “record” in the help or :=:

Myfile1:record :=: myfile2:record

Any help please ?
Clarion 10

It’s all in the Help Sim - use the Index and RECORD

and the Search box with ‘Deep assignment’ to find help on :=: