Dear Miss Manners: Lately I've found that chain restaurants, and even local ones, have a tip line on the credit card form — when the restaurants provide no service.

I place my order at a register, pick up my food when they call my name or number, and then bus my own table. They clearly expect you to do this, as they provide receptacles and signs with instructions.

They have a tip jar for use if you don't use a credit card. I understand this is a practice at coffee shops to show appreciation for the artistic ability of the barista, but for a plain cup of coffee? I've also found this practice when I pick up a meal to go.

I understand this is to offset the fact that they do not pay a living wage to the employees, but am I required to tip when no service is rendered? I usually end up putting $1 in the tip jar or on the tip line, which makes me feel churlish and taken advantage of at the same time.

There are a number of factors to weigh when deciding whether or how much to tip, but Miss Manners does not consider that the little tip-bait traps have become so prevalent should be among them.

The most important element is whether the job is structured so that tips are counted as part of the workers’ wage. (For that reason, owners of businesses are not tipped, although many have also come around to expect it.) Miss Manners believes that service charges should be built into the customers’ bills, not left to their discretion. If that is not being done, however, she cannot countenance customers withholding such basic compensation.

Less important, to Miss Manners and practically no one else, is the quality of the service. Blatantly bad service should be reported, she believes. But before penalizing someone merely for having a bad day at work, one should reflect about whether one’s own income is affected by an occasional lapse.

And while it is generous to reward good service beyond the customary minimum, it is insulting to maintain that workers are so unprofessional as to require extra bribery to perform their jobs well.

So you should tip when you think it is right. But do not have qualms about not doing so only because the business is trying to make you feel guilty if you do not.

Dear Miss Manners: While discussing with some colleagues a family member's plans for a black-tie wedding and reception, someone noted that gifts are not to be given if the wedding is black tie. I have never heard of such a thing, and my husband and I have already purchased a lovely gift. Clarification of this matter would be appreciated.

Amazement, rather than clarification, is the only thing Miss Manners can provide. Where do these bizarre ideas arise? What possible connection could there be between the clothing worn and the presents?

Folks, please stop making up absurd “rules” that you try to pass off as required by etiquette. Miss Manners has enough trouble making people obey the real ones.

New Miss Manners columns are posted Monday through Saturday on washingtonpost.com/advice. You can send questions to Miss Manners at her website, missmanners.com.

2018, by Judith Martin