Hi there,
I've had a read of your GridFTP v2 document and it all looks very good. The only comments I have are pretty minor typos 
and such like:

1.  Page 4, "eXtendedBlockk (X-Block) Mode".
The 2nd bullet point says "...network connections as resource". Should this say "as a resource" or "as resources" 
perhaps?

2.  Page 4, "Data Streaming".
The 2nd line says "...parallel channels in the same time.". Should perhaps say "at" rather than "in".

3.  Page 4, "Data Block Format".
The 1st bullet point says "Transaction ID is used to hold". 
"Hold" what? The sentence seems to be unfinished.

4.  Page 5. Table, row 2, column 3, "Descriptor|Contents".
Why is there "(?)" in the text?

5.  Page 9.  "Active Receiver".
The 7th line of this paragraph says "...at least one of the sender hosts was open successfully,". I assume it should say
 "opened" rather than "open"?

6.  Page 9.  "Active Receiver".
The 8th line of this paragraph finishes by saying "...should not be considered an error by the receiver." 
Does this mean that if only one data channel opened successfully that all the data would then be sent down this one (
open) channel?

7.  Page 13. Line 4.
The first bullet point on this page says "cksum - is mode X is...". Should say "if mode" not "is mode".

8.  Page 13. "Examples of Communication".
In all the examples the digits of the port address are separated by commas, whereas the 2nd bullet point of the Command 
Syntax section (on page 12) says the data port address specification will be in the standard form "a.b.c.d.e.f", i.e. 
with full stops. Is this correct, since the examples don't seem to use the defined command syntax?

That's all!

Cheers,
Stephen Davey.

NeSC, Univ. of Edinburgh.