Template:Allbooks category/core
This template implements the initial phase of internal processing for template {{Allbooks category}}. On entry here, all that is known is the expected name for the subject page associated with the allbooks category.
Usage
There is one parameter, assumed to be specified and non-blank.
subject— the name expected for the associated subject page. This is just the name of the allbooks category without the "/all books" suffix.
This template checks that the subject page exists and is correctly formatted for extracting its parameters; if not, it calls {{Allbooks category/error}}. If all is well, extracts the parameters from the subject page and calls {{Allbooks category/core2}}.