This article is from the Apple II GNO FAQ, by Devin Reade with numerous contributions by others.
A#5.3: Anything you add to your GNO installation beyond what is in the base installation should go into the /usr/local hierarchy. This will facilitate future updates, in that you will only have to replace those directories used by the GNO base distribution, and your customized files will not be overwritten. There are some exceptions to this. For example, /etc/passwd, /etc/namespace, and a few other files that have to be customized do not and will not reside in the /usr/local hierarchy. However, these will be kept to a minimum and will be explicitly mentioned in future release notes. If your installed man(1) cannot cannot handle manual pages in more than one directory hierarchy, then you need to upgrade your man to version 3.0 or later. GNO v2.0.4 CAVEAT ^^^^^^^^^^^^^^^^^ When GNO v2.0.4 (and earlier versions) was released, there was no attempt made to have users put add-ons in the /usr/local hierarchy. Therefore, if you're currently running GNO v2.0.4 it is likely that you have a lot of custom items in /bin, /usr/bin, /usr/man, and related directories. This is complicated by the fact that various packages that are considered "standard" (such as the Multiuser Update) were not part of the base GNO v2.0.4 distribution. If you are in this situation, then I suggest that you not worry at this time about moving existing programs to the /usr/local hierarchy. Instead, defer this to when GNO v2.0.6 is released. In the interim, there is nothing stopping you from using the /usr/local hierarchy for anything new that you download ...
 
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