Two things as far as the OTU goes.
- The Imperial xBoat network.
This is essentially a file transfer network. Yes, messages, but besides that all sorts of data. In all manner of formats which may all be incompatible with each other.
- The Office of Calendar Compliance (OCC)
From T4, we know there is The Office of Calendar Compliance, which enforces standards Imperium-wide with the ability to impose extreme penalties to non-compliant systems. The purpose of which is to encourage trade between systems. Specifically listed in the text is the standard Imperial Calendar and weights and measures.
HOWEVER
I see the OCC as the ISO, but with teeth. From my computer work experiences which stems from the '80s to the '10s I add this.
One of my previous jobs was to write file transfer scripts to send expense reports and files from Chase Bank to Federal agencies and groups like the Deparment of Energy, NASA, and a portion of the US Senate. Federal accounts using Chase bank. My NDA is long expired so no worries. The files were being sent to in all combinations of EBCDIC or ASCII from Chase mainframe systems or Chase Windows Servers to a gobblety-gook of government destinations. Despite that there were two unifying elements.
One was the software used to perform the transfers, something called Connect: Direct. C: D has been around since before the '90s when it was called Network Data Mover (NDM). It is written for different platforms and also performs EBCDIC or ASCII (or the reverse), CRLF add/removes and some other basic translations. It also provides unified logging/messages of every single bit of minutiae involved in the transfer to sender and receiver.
The other is the standards the Internet itself uses for comunication.