Saturday In The Park

Ah, that explains it very nicely. Thank you very much. But I have to ask this: You say "computer-generated sepia is a no-no." Evidently, some old photos acquire this color over time. I can't tell it if they do, but as long as it's not computer-generated sepia, it's all right for the group?

These are hard questions that you ask ;) But you already know it, don't you? ;)

Many old black and white prints turn brown-yellow because of their old age (papers do this after many years of being exposed to light). Some old prints has this sepia toning from the very beginning (because of chemistry used then) and this color can fade or change in many surprising ways.
Some of them can find their way into "The Black & White" group as exceptions. It really depends on how they esthetically fit into the group's general outlook. I am making these decisions individually trying to answer a question: "Does it feel right for the group or not?"
"Not right" usually means a submission under inspection would stand out like a sore point because of the color involved.
I am not able to give you exact measures behind those decisions, but let me think about them. Give me some time. I'll be back with some other answers, I promise!