1.—Don't stand in, or cross, your opponent's line of vision when he is in the act of playing.
2.—Don't rattle the chalk box or pull down the chalk if suspended from the ceiling whilst your opponent is playing.
3.—Don't drop your cue, just as your opponent is in act of striking.
4.—Don't ask your opponent to take refreshment, just as he is set for a break. It is mistaken hospitality.
5.—When your opponent is in play and probably leading don't make audible remarks to some bystander. It isn't polite and although not meant to distract his attention you are apt to be misjudged.
6.— Don't ask the marker the state of the game whilst your opponent is in play; wait until he finishes. (Onlookers are the chief offenders in this case).
7.—Don't keep nagging your opponent about his flukes and luck, you get both yourself often enough.
8.—Don't have a magnifying eye for your opponent's flukes and a microscopic one for your own.
9.—Don't when holding a long lead become ultra-generous and sympathetically call out "Hard lines" when your opponent does not go within a mile of the shot. He won't appreciate your goodness?
10.—Don't strike a match in your opponent's line of vision.
11.— Don't audibly say "He's finished now," when a difficult shot threatens to end a good break.
12.—Don't go dodging about the table when your opponent is in play. It puts him off.
13.—Don't laugh sarcastically when your opponent declares he played for a certain shot. You expect to be believed yourself.
14.—Don't keep on muttering and grumbling because your opponent is having all the luck that is going. Be patient, your turn will come.
15.—Don't take away the credit of your opponent's victory by some such remark as "Well, you are a fluker" or "You are the luckiest player I ever struck."
16.—Don't go smiling and chuckling, when things are all going your way and get an expression on your face fit to make milk sour when things are going against you.
17.—Don't forget to give your opponent all credit for a good break or an extra good shot.
18.—Don't sulk when you are beaten.
19.—Don't grumble about your starts in handicaps.
20.—Don't keep remarking on each shot—keep quiet.
21.—Don't question the marker's decisions.
22.—Don't keep discussing politics or the latest football match whilst the game is on.
23.—Don't ask your opponent for a cigarette, whilst he is in the midst of a break, nor yet offer him one yourself.
24.—Don't lie down, when you are a long way behind—in other words "funk." You never know how the balls will run. Wait.
25.—Don't belittle your opponent's efforts.
26.—Don't forget to say "Thanks" or "Good-night" when you have got a good hiding. 'Tis childish not to.
27.— Don't hold an inquest over the game afterwards, trying to show just where your opponent had a most egregious fluke which altered the whole complexion of the game, otherwise you would have won. Be a sportsman.
28.—Don't forget to read, mark, and inwardly digest these behests and thus extract all the enjoyment possible out of the best of all indoor games—billiards. "'Tis the little things that tell," as the immortal Dan Leno had it.