So I’ve got some slx code m675b. And they are ispec b.
Also I have some deor code m615.
The deor are identical looking lever clamp as the slx? With the hole top and bottom. So ispec b.

Fairly miffed with shimano as I got some ispec a levers off here based on the code.

Am I missing something.
I’ve looked at all the threads and the only thing I can think of is shimano did not put a “b” on the early b levers.

Can anyone shed some light on this?

I think the Deore came out after I-spec A had already been superseded by the B version, I could be wrong.

As B shifters will fit A levers they don’t see they need to differentiate, and Shimano does not see any need to cater for used parts sales.

But the newer SLX have a b on the code?

But the SLX were made in both A version, M675, and B version, M675B.

The Deore have only been produced as the B version.

Ahh sounds a good reason.