Where I come from my SOP requires:

(From TX SOP)

(4) report as in need of repair spacings between intermediate balusters, spindles, or rails for steps, stairways, balconies, and railings that permit passage of an object greater than four inches in diameter; and

(5) report as in need of repair the absence of safety glass in hazardous locations.

My SOP does not say anything about what the current or past code is or was.

I did an inspection last year (22 year old home) where the seller told the buyer that they were'nt going to and were not required to bring anything up to current code and that the inspector (me) was out of line by listing certain issue as being in need of repair. To which I replied (to my client) that:

Although nothing in my report was "required" to be repaired by the seller,
many of these "current code" issues were related to safety concerns and that many were also required by the state SOP to be listed on the report.

I went on to say that code changes come into effect many times because of safety concerns that may not have been realized or acknowledged at the time of the house was built and it is my duty to make the client aware of the any issues that I see that may affect the clients safety.

In my opinion, if an inspector is not looking out for the safety of their client, they are not performing thier responsibilities as a home inspector.

Eric