Why does the reference check ignore a space after a book name?

Question

A: When the space is part of the name for a different book.
Someone had a mysterious message in a cross reference, something like this (I recreated the issue in a test project) 

Why does Paratext think a space is missing between "John" and "12:12-19" ?
Because if the book name for 1John is "John 1", Paratext parses "John 1" as the book name, then looks for the space before the chapter verse, and does not find one. (If the reference had been to John's gospel, chapter 1, Paratext would say "invalid book/chapter separator", because what follows the book name "John 1"  has no chapter number. 
So if your project has the number after "John" for the three epistles of John, don't have a space between "John" and the number. 

Answer 1

Would this be a place where you could use a special space between the John and 1? Turn on White Space option and use a no-break space in the name.

Comments

Yes, that works.
After putting a no-break space (NBS) in the book name for 1 John, Paratext sees the difference between John<space>1  and John <NBS>1

(I do not really think there is a parallel between 1John 2:11 and Jesus' triumphal  entry, I am just demonstrating that the link works).