Courtesy and honorary titles - clarification?

Hi. From the guide ( https://help.imdb.com/article/contribution/names-biographical-data/names/GSA3M6SFHRAERXZ3# ): "Courtesy titles like Mr., Dr., Sir, and degree indications like Ph.D., are not considered part of the name, and are not included in the primary name, even if that is how the name appears on screen. They are included as alternate names. (Exception: In the silent era, it was not unusual for women to be credited as, i.e., Mrs. John Smith -- in such cases, Mrs. is an integral part of the name, since John Smith is an entirely different person.)." I came across with an older documentary from the 1960s, where all the interviewees are (only) being "credited" by the narrator (meaning, that there are no captions/titles, nor names listed in the end credits) and several of them use a slightly old fashioned expressions like "major Smith" (the person is a retired major, with the surname "Smith") or "mayor Smith" or (the official in a municipal government) or "professor Smith" (academic rank). With "old fashioned" I mean that back in the days people probably tended to use these more often. My question is that where do we "draw the line" with these so-called "courtesy and honorary titles", academic ranks, political officials, etc? Which are actually added as "alternate names"? I have been very cautious in adding something like a "major" as an alternate name, but perhaps I'm wrong. Thanks.