A sample of a referral tree might look like this:
---- Please refer to the following [[AAB]] [[Library Data]] articles for further information: <br> '''[[Starship]]:''' * [[Drive]]s ** [[FTL]] ** [[NAFAL]] ([[STL]]) * [[Starship|Starship Drives]] ** [[G-Drive]] ** [[HEPlaR]] ** [[J-Drive]] ** [[N-Drive]] ** [[Rocket Drive]] ** [[Z-Drive]] ----
They are placed under an infobox (...if one exists for the article type) and the article's synopsis at the top of an article.
It is possible for multiple referral trees to be added where possible, but it is preferred to minimize the trees henever possible. It's a very subjective matter.
With several thousand articles spanning over 2,000 publications and 40 years, referral trees are necessity to enable readers to more easily explore a subject.
Most referral trees are grouped around category tags that share common subject matter or themes.