Let’s see if I can clarify Cub Scouting terms.
Youth and volunteer leaders appear to be grouped differently. Youth participating in the Lion, Tiger, Wolf and Bear sub-programs are Cub Scouts. Those in the Webelos sub-program are Webelos Scouts. All den leaders in the Cub Scouting program are Cub Scout Den Leaders (and Cub Scout Leaders.).
All Scouts registered in the Cub Scouting program are Cub Scouts (also know as “Cubs”) or Webelos Scouts per the Language of Scouting and BSA Style Manual*. revised November 2018. Per this manual a den is:
A neighborhood group of four to eight Cub Scouts or Webelos Scouts that meets periodically, usually once a week, and is part of a Cub Scout pack.
Image above: © 2019 Boy Scouts of America, from How Cub Scouting is Organized (downloaded 2019-07-06)
All Den Leaders are Cub Scout Den Leaders which is a sub-set of Cub Scout Leaders and other leaders in the pack are also Cub Scout Leaders per the Cub Scout Leader Book (2018). They all wear the blue shoulder loops (item 677) on a field uniform.
In the Lion Den Leader Guide (2018) den leaders are referred to as “Lion den leaders”.
In the Tiger Den Leader Guide (2018) on pp. 8-9 has:
Cub Scout den leaders (all den leaders) work with …
Lion and Tiger den leaders …
Cub Scout den leaders … (Wolf and Bear den leaders)
The Webelos den leader …
It appears in at least one publication “Cub Scout Den Leaders” (each word beginning with a capital letter) was used to refer to all den leader and Wolf den leaders and Bear den leaders are referred to as “Cub Scout den leaders” (with the words den and leader being in lower case.). However, this is not a consistent practice across publications.
The Den Leader Training Award Progress Record, form 511-052, 2018 Printing, released in September 2018 has the following instructions:
❏ Tiger den leader ❏ Cub Scout den leader (Wolf/Bear)
❏ Webelos den leader ❏ Lion den leader
Note: This award can be earned in each position, but tenure may be used only for one award.
“Lion, Tiger, Wolf, Bear, and Webelos” are sub-programs of the Cub Scouting program. They are also ranks that Cub Scouts in those sub-programs are working towards. The Guide to Advancement, Mechanics of Advancement in Cub Scouting, 220.127.116.11, also refers to Bobcat and Arrow of Light as ranks. (Cub Scouts working towards Arrow of Light are in the Webelos sub-program.) A Cub Scout in the Tiger sub-program first earns the Bobcat rank, then the Tiger rank.
BSA has defined different colors to identify BSA, programs and sub-programs.
The den leader titles (and position codes) used in the membership database do not define the program and sub-programs. They do allow BSA to create sub-program contact lists and may be used for some analysis of packs and filtering of data.
Some world-wide history is available in the Cub Scout WikepediA page. From what I have read, I believe den leaders in BSA were older Boy Scouts, then Den Mothers, then Den Leaders. This discussion topic is about Den Leaders. If you wish to continue discussing Cub Scout history or the current Cub Scouting program, may I suggest doing it in another discussion topic?