i said:

in z.m.l., anything surrounded by two or more blank lines is a paragraph. 

pardon me. that's a goof. anything preceded by _one_ or more blank lines is considered to be a new paragraph in z.m.l. i sometimes accidentally mix up "blank lines" and "line-endings". _two_ consecutive line-endings (i.e., _one_ blank line) delineates a new paragraph. two blank lines constitutes a "thought break". three or more blank lines constitutes a new section. (three is more like a "subsection", while four marks the lowest-level section, five the next-lowest, etc.)

In z.m.l., anything surrounded by two or more blank lines is structured text.

wait a minute! _i_ make the rules for z.m.l., not you. :+)

When you can recognize a paragraph,

i can recognize a paragraph. i just explained how, up above.

and distinquish it from a title

"distinquish" is a nice word. what does it mean? to distinguish and then squish? :+) i can recognize a title too, and thus "distinguish" it. i just explained how, up above.

or a block quotation inside of a paragraph,

what's so hard about that? it's very easy to recognize the block quotation -- because those things are indented in z.m.l. -- and if the paragraph above it was not terminated, then the block quote is "inside" of it. (well, due to how z.m.l. defines "a paragraph", the block-quote itself is its own "paragraph"... but there's no need to discuss these semantics.) at any rate, the z.m.l. viewer-program is happy to show you a listbox of all the paragraphs in the file, nicely numbered and everything. or it will show you a list of all the words in the file, also nicely numbered. and at the bottom of each page that it shows you, it gives the character-numbers and line-numbers of the range of text on that page. so an end-user will have an easy time quantifying exactly where they are. but you know what? very few of them ever have a need.

no matter how many blank lines surround them

in z.m.l., blank lines are the very thing that _define_ paragraphs -- and titles too. so i am afraid that z.m.l. will never "be able to" do what you are asking. but...

then I'll be impressed.

...my goal is to render e-books properly, not impress you. -bowerbird