Word choice: An example that is used throughout a thesis

I am writing a thesis in which there is an example that will be used throughout the thesis (repeatedly) to illustrate various methods or various aspects of the theory. I will introduce the example in the first chapter and want to use an adjective for it to emphasize the fact that it will be used throughout the thesis. But I don't know the word. I'm thinking of "standing example" or "recurring example" but they don't sound right to me. Which word should I use in this case?

I guess 'running example' is also an option.

Usage: http://www.gnu.org/software/sather/docs-1.2/tutorial/employee.html

Though it's difficult to say without knowing a little more, such as the topic, or how the example is to be presented, these are the words that come to my mind

Standard Definitive Authoritative General Generic Average

I also like JLG's suggeston "key".

I suggest referring to it as the principal or primary example, from that sense of primary that means "That which is placed ahead of others". You'd write, "The primary [or principal] example used in this thesis is ...", and later, "Referring again to our primary [or principal] example ...", etc.

If the example is in some sense standard or definitive, consider calling it

• a canonical example, meaning a standard or normal or prototypical presentation of something;
• a model example, following the sense "A praiseworthy example to be copied";
• a reference example or reference case.

If you want to emphasize that the single example covers or includes aspects from many others, you might refer to it as inclusive, all-inclusive, a catch-all or umbrella, versatile, or overarching.

All that said, if the example contains a distinctive keyword or keywords in its description, for example Westgate, then use it or them in your references. At the outset, you might say "The principal example used in this thesis is the following Westgate scenario...", and thereafter, "Referring again to Westgate, ..." or "Referring again to the Westgate scenario, ..."