Awhile back, someone in my household brought home a new book on etiquette. I'm not sure why: Maybe they thought my manners could use some polishing.

Whatever. I have been thumbing through the thing and along about page 49, I realized that this--like most such manuals I have seen--is written for adults, not for children. This may be a serious oversight. I think we should have more books on deportment written especially for youngsters.

Most grown-ups I know already have fairly passable manners. If you ask an adult to pass you the salt, he usually doesn't put the shaker behind his back and say, "Guess which hand it's in." And when you give an adult a gift for Christmas or birthday, he or she tries to act as if it's the one thing they have longed for all life through. They don't burst into tears and wail, "A wallet? I wanted a pony!"

I'm probably not the one to tackle an entire book on Thumbrules for Tots, but in the interest of smoother civilization, I would like to make a few brief suggestions to the younger set:

• When you are a dinner guest and the hostess serves a dish you do not like, decline by saying, "No, thank you--I really wouldn't care for any spinach casserole." This goes better than holding your nose and yelling, "Don't give me any of that yucky green stuff that looks like it's already been ate once."
• When eating spaghetti--at home or away--roll the pasta neatly onto the tines of your fork. Do not put one end of the spaghetti into your mouth and suck.
• Do not bring water pistols, slingshots or wild animals to plays, church or music concerts.
• Do not push younger children down stairs or off porches. Also, do not hit them with pop bottles, roller skates or history books.
• When answering the telephone and the caller asks to speak to one of your parents, reply: "Please hold on--I'll see if he can come to the phone." Do not say, "Hold on and I'll try to get him up--he's flaked out on the couch."
• Respect the property of others. Do not put sand in your mother's cold cream or use your father's new belt to make a leash for the dog.

This by no means is a complete list of do's and don'ts for youngsters,

of course, but I had to start somewhere. Feel free to amend or augment these points to suit your own family situation.