It's impossible. See, the name of the tag (in fact, any link, the same goes for branches) is considered as the name of the file system object created in the folder of $GIT_DIR/refsyour repository. This object stores the hash commit to which the tag is bound.
With a tag foo, it's easy - a file foois created in $GIT_DIR/refs, nothing much to wonder about.
foo/bar, , : foo, - bar ( , -). :
[ ] / ()
, - - . , 1.16.0, 1.16.0/anything. 1.16.0/0.0.1, . - _.