ALL
There are two distinct specifications which can be included in a PUT statement using the same token, ALL.
One ALL is strictly a feature of the PUT statement. According to the documentation: it "writes the values of all variables, which includes automatic variables, that are defined in the current DATA step by using named output."
The other ALL is usable in many SAS contexts. It is documented in SAS Language Reference: Concepts, which states that it "specifies all variables that are currently defined in the current DATA step."
https://communities.sas.com/t5/SAS-Communities-Library/PUT-Statement-with-ALL/ta-p/475999