find-tag-marker-ring

find-tag-marker-ring is a variable defined in `etags.el'.
Its value is

(0 0 .
   [nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil])

• This variable is an alias for `xref--marker-ring'.
• This variable is obsolete since 25.1;
  use `xref-push-marker-stack' or `xref-pop-marker-stack' instead.

Documentation:
Ring of markers to implement the marker stack.