What does REF mean in programming languages?

Question

Programming languages

I was led to this question by a rule from the grammar of one language, namely:
<kind>::=BOOL|INT|REF<kind>
It turns out that both simple BOOL, INT and records of the form REF BOOL / REF INT are possible. This confuses me. Maybe REF says that there is a description of the variable. But then, logically, the rule should look like this:
<kind>::= REF BOOL | REF INT
Variable of type BOOL or variable of type INT.
I look forward to your feedback on this rule.

Answer 1

REF - reference, link, pointer.

Answer 2

<kind>::=BOOL|INT|REF<kind>
It turns out that both simple BOOL, INT are possible, as well as records like REF BOOL/REF INT.

It doesn't follow from the passage you quoted.