Following the suggestion from the documentation team: https://github.com/3scale/zync/pull/142/files#r264327709
The links we have right now there, hardcoded, point to documentation from 2.4, and they will get outdated because they are plain text.
The goal of this Jira issue is to make them autoupdated and to work when we update the version.
porueesq1@redhat.com told me how to do this:

if you use placeholders in a master file, you just change the value of the variables and this is reflected in all the places where these variables are used.
For 2.4, we have this master file:
https://github.com/3scale/Red_Hat_3scale_Documentation/blob/2.4.x/docs/topics/templates/document-attributes.adoc
you'll see here that we have variables such as: ProductName, ProductVersion
this is to ensure we use the same name in all the docs (well, we ARE still trying)
also, for crossreferences.

I also asked her how to reference to this file, and she said:

ok, this question takes us to the notion of chapters.
for us, a chapter is similar to a directory, for example, release notes
https://github.com/3scale/Red_Hat_3scale_Documentation/blob/2.4.x/docs/release-notes/master.adoc
the master.adoc file is the file that assemblies all sections of the chapter.
this master.adoc file refers to the document-attributes.adoc file (aka master file of variables).