Note: – The string [inside-the-brackets] is the meta-key in the WordPress database etc..

 

• Server Site – [server-site] – The actual location of the files being embedded and/or linked.   The Server Site might or might not be a Posts Blog or a Posts Multisite.
• Repository Site – [repo-site] – The virtual location of the files being embedded and/or linked.   The Repository Site is linked to a Server Site by a changeable link in the Central Control.
• Mirror Site – [mirror-site] – The Repository Site (and hence the Server Site) as seen from the Posts Blog .   The Mirror Site is linked to a Repository Site (or a Virtual Site) by a changeable link at the Posts Blog settings.
• Virtual Site – [virtual-site] – The Repository Site (and hence the Server Site) as seen from a Posts Multisite.   When this is enabled, a Mirror Site is linked to a Virtual Site (rather than a Repository Site) by a changeable link at the Posts Blog; the Virtual Site further redirects to the Repository Site by a changeable link in the multisite Network Admin settings.
• Resource Name – [resource-name] – The name by which the resource is provided by the Server Site. Usually this is a filename with extension.
• Resource ID – [resource-id] – The name by which the resource is known at a Posts Blog. Frequently this is a filename without extension.
• Filex – [filex-name], [filex-exp] – A named Regular Expression (PHP 7.0 PCRE REGEX) used to dynamically extract a part of a fully qualified resource URL for use as a Resource Name, Resource ID, or Branch.
• Nominal URL – The fully qualified URL of a local or external resource which is specified in the shortcode etc. instantiation. 
• Primary Branch – [primary-br] – A partial  URL, an internal string of a URL, used with the Server Site URL and the Resource Name to make  a full Resource URL.  If the use of Primary Branch is enabled at both the Server Site and the Mirror Site (as seen from the Posts Blog ), the Primary Branch will be identical in both places.
• Secondary Branch – [secondary-br] – A partial  URL, an internal string of a URL, used with the Server Site URL and the Resource Name to make  a full Resource URL.  If the use of Secondary Branch is enabled at both the Server Site and the Mirror Site (as seen from the Posts Blog ), the Secondary Branch will be identical in both places.
• Tertiary Branch – [tertiary-br] – A partial  URL, an internal string of a URL, used with the Server Site URL and the Resource Name to make  a full Resource URL.  If the use of Tertiary Branch is enabled at both the Server Site and the Mirror Site (as seen from the Posts Blog ), the Tertiary Branch will be identical in both places.
• Resource URL – [resource-url] – The full URL of a resource at a Server Site.  If all options are enabled, it is composed of <server-site> /  <primary-br> / <secondary-br> / <tertiary-br> / <resource-name>
• Central Control  – The structure by which control of all mirrors effected. In a simple single Posts Blog system (non-multisite), this is simply in the local Options table of the WordPress database.  In a multisite system, this will be in the Site Options table of the multisite WordPress database. In a multiple multisite (or multiple single site) configuration, these local tables are updated from a central resource by chron jobs.
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