Or at least explain to me where my thinking is wrong. Is that so much to ask?
Why do people say this kind of stuff?
Presentation Layer: Layer 6. This layer responds to service requests from the Application Layer and issues service requests to the Session Layer. The Presentation Layer relieves the Application Layer of concern regarding syntactical differences in data representation within the end-user systems. Note: An example of a presentation service would be the conversion of an EBCDIC-coded text file to an ASCII-coded file.
My understanding is that a presentation layer is an abstraction of the data, ie a database to the code that pulls and displays the content in the database. Mark has that. He uses Movable Type, a weblog content management system that stores the text in a database. Can you embed html in the text? Yes. Can you just as easily use a search and replace to remove or change that markup? Yes. What is the alternative? For Mark to create his own alternative markup language representing quotes, blockquotes, citations, links, etc. and then to translate that on the fly or at build time into HTML / XHTML / XML / RSS. Why not just use HTML or XHTML to begin with? Oh, that's right, that's what he's doing. Am I missing something here?
Unfortunately I can't tell if you disprove of what I said or if you disprove of the wording from the MT site. Explain! :)