daf bit: B'rachot 43

Our rabbis taught: six things are unbecoming for a scholar:

• He should not go abroad scented. R. Sheshet says this applies to his clothes but not his body because perfume hides body odor. There is a dispute about whether hair is like the body or like clothing.
• He should not go out at night alone. This is to avoid suspicion. But he can go out if he has an appointment with his teacher because people will know that.
• He should not go abroad in patched sandals. This applies to the upper but not the sole, and applies when he is in public but not when in a home. Also, this applies only in summer; during the rainy season it's ok.
• He should not converse with a woman in the street. R. Chisda says: not even with his female relatives, because people won't necessarily know they're his relatives.
• He should not take a set meal (meaning one where you recline, apparently) with ignorant people. Why? Because he might be drawn into their ways.
• He should not be the last to enter the beit midrash (study hall). The g'mara does not here address the problem that somebody has to be last. Perhaps "scholar" means only one who is accomplished, and there are always students around who have not reached that level? Or perhaps the last two enter together so neither is "the last one". Those are guesses.

Some add that he should not take long strides or carry himself stiffly; the latter is akin to pushing against the heels of the Divine Presence. (43b)

We are not told how a community that doesn't know who his female relatives are would know that he's on his way to study at night.