When a template directly introduces a link to a target page, the "what links here" list for the target page should list the template as a link to the target, but it should not list a page that uses the template as links to the target (unless the using page also has direct links to the target.)
Alternative: Treat links generated by a template similarly to links via a redirect: that is, list the template, and then list all pages linked via the template indented under the template link.
Justification: "what links here" is used by people who move a page to find and repair all of the links to the page. We also use "what links here" to gauge the relative importance of several pages when determining whether a particular page should retain the "main title" when disambiguation is needed. A third major use of the "what links here" is to generate the list of "most needed articles." In all three cases, the resultes rae severely distorted when th epage is linked from a template. For example, a completely obscure Football coach named Clyde Snerd suddenly has 50 links when he is one of 50 football coaches listed in a template of "coaches of the Lower Smedley football club." If I move his page to "Clyde Snerd (football coach)" I must then check all 50 pages to see if any of them have non-template references.Changiong e template first does not help, because the resulting updatea process (apparently) runs in the background and can take quite a long time. The result on the "most wanted articles" list is dramatic: all of the topmost "most wanted" articles are due to inclusions in templates.
Proposed in #community-wishlist-survey-2016. Received 37 support votes, and ranked 41 out of 265 proposals. [[ https://meta.wikimedia.org/wiki/2016_Community_Wishlist_Survey/Categories/Search#Hiding_links_through_templates_in_.22what_links_here.22_results | View full proposal with discussion and votes here ]].