what does curly brackets mean in stata help files?

[Larry Kong]

I know square brackets mean optional components, vertical bar means OR, but what do curly brackets {} mean?

An example:
"
rangestat slist [if] [in] , interval(keyvar low high) [ options ]

where slist is composed of one or more of the following

(stat) { varlist | new_varname=varname } [ { varlist | new_varname=varname } ...]

(flex_stat) varlist

"

[Nick Cox]

They mean “choose one from this list”.

[Larry Kong]

Thank you for your reply, Nick. but isn't that what the vertical bar "|" (OR) mean?

They mean “choose one from this list”.

[Nick Cox]

{ } delimits the list; | separates the items. Choose one: { rich | beautiful | excellent coder }

[Larry Kong]

Thank you again, Nick! The example is excellent.

{ } delimits the list; | separates the items. Choose one: { rich | beautiful | excellent coder }