Dept. of Subtle - Type Catalogs and Quotation Marks

I was recently asked to provide a couple sample family files that used Type Catalogs and imperial units. I made them and shipped them off. I got a reply back shortly thereafter asking about some odd behavior. Here's what one Type Catalog looked like:

,Length##LENGTH##FEET,Width##LENGTH##FEET,Height##Length##FEET
2'0"x 2'0x 2'6",2'0,2'0,2'6
3'0"x 3'0x 3'0",3'0,3'0,3'0
4'0"x 4'0x 3'0",4'0,4'0,3'0
5'0"x 5'0x 4'0",5'0,5'0,4'0

If you look closely you'll see that I left out the "inch" mark for the middle dimensions of the Type Name. I didn't do it on purpose. When I load the family I get this dialog:

When I realized (more accurately, was asked why...) I left the "inch" marks out I fixed it. The result was this:

The Type Names were squished together into two types instead of four. Curious. The answer lurks in The Families Guide (separate download, not in Help unfortunately). Methinks that the Families Guide ought to be available in the same online format as the rest of the help documentation too!

Listed among the rules on page 85 of the Creating a Type Catalog chapter is:
You can use single or double quotes. If you are using double quotes, you need to enter "" for Revit Architecture to understand it as double quotes.

All I had to do was add a second set of " marks to the middle Type Name. I could also use two single quotes instead. If you get some weirdness with Type Catalogs take a quick trip to the "rules". The fixed file looks like this:

,Length##LENGTH##FEET,Width##LENGTH##FEET,Height##Length##FEET
2'0"x 2'0""x 2'6",2'0,2'0,2'6
3'0"x 3'0""x 3'0",3'0,3'0,3'0
4'0"x 4'0""x 3'0",4'0,4'0,3'0
5'0"x 5'0""x 4'0",5'0,5'0,4'0

Revit doesn't seem to mind the others but technically I should add the extra quotation marks to the others too.