What is !! (double exclamation marks) in YAML?

I have this snippet in a longer YAML:

config:
  operations: !!map

IntelliJ marks the !! as error (expected key-val pair or array item), probably a false positive.
I wanted to understand more about it so I opened YAML specifications but I am still not sure about its use.

Is it used to specify a type or something else?

>Solution :

On the document you linked, it says that !! is a Secondary Handle or a Core type (Generic Mapping)

Secondary Handle

The secondary tag handle is written as “!!”. This allows using a compact notation for a single “secondary” name space. By default, the prefix associated with this handle is “tag:yaml.org,2002:”.

Further example usages on https://yaml.org/refcard.html is as follows

…
‘!foo’ : Primary (by convention, means a local "!foo" tag).
‘!!foo’ : Secondary (by convention, means "tag:yaml.org,2002:foo").
…
Core types: # Default automatic tags.
‘!!map’ : { Hash table, dictionary, mapping }
‘!!seq’ : { List, array, tuple, vector, sequence }
‘!!str’ : Unicode string

More types:
‘!!set’ : {cherries, plums, apples }
‘!!omap’: [ one: 1, two: 2 ]

In your example, it defines that operations is a map that can have other values.
Can see more info here Generic Mapping

Block style: !!map
  Clark : Evans
  Ingy  : döt Net
  Oren  : Ben-Kiki

Flow style: !!map { Clark: Evans, Ingy: döt Net, Oren: Ben-Kiki }