There are special word lists which are called upon at various points in the Metamorph search routine and influence the way your search requests are processed, as well as which hits are deemed valid and presented for viewing. These lists can be tailored to user specification if desired.
While it is encouraged that you edit equivalences as often as you wish to reflect what you have in mind to search for, it should be clearly understood that editing equivalences that go with search words is a very different activity from editing the special word lists which govern Metamorph's approach to linguistically processing the English language.
The default content of the special lists is the result of much research on the part of the program developers, and reflects what has been locked inside Metamorph for a long time for effective use in most situations. Still, these lists are open to editing to conform to program purpose: that just about everything that is related to how Metamorph processes language is subject to modification.
The special word lists are what the program classifies as: Noise (which also includes Pronouns, Is-associations, and Question words), Prefixes, Suffixes, and Equiv-Suffixes.
For example, here is the default Pronoun list:
anybody ourselves you
anyone she your
The content of this list is stored in ASCII format in a Metamorph profile, and can be edited there, if you have an application set up which can read a special profile. Otherwise trust the internal defaults of the program, and override them with an inline APICP directive if you need to change them, as shown under Question Parsing.