What does gen variable=group(variable1) create?

[Li Sea]

I intended to create a different value for each unique value of variable 1 and wrote

gen variable=group(variable1)
o know the correct way of doing it is with "egen" instead of "gen"

variable1 takes numeric values.
There are around 300 unique values of variable1

egen generates it correctly - values from 1 to 300.
but gen also generates it without promting any error - values from 1 to around 4800. there doesnt seem to be any recognizable pattern that i can tell how those values were created.

i am trying to figure out whether there is any system behind those values (incidentally results with those 4800 f.e. are much better than with 300).

Thanks for your help!

[Nick Cox]

This group() went undocumented in Stata 9. See https://www.stata.com/statalist/arch.../msg00260.html for more of the story.

In general egen functions and functions that work outside egen are completely disjoint, even if they share the same name.