1) Secret identies are sacrosanct: In a world of corporate endorsements and lessening privacy, where the police can track you by freeway video tape, facial recognition software, fingerprints or DNA, secret identities seem less and less possible.  Yet it is the super hero's perview to maintain their identity for as they as they are able. A secret identity is a hero's shield, their first, best manner with which to protect their friends and loved ones.  Revealing a secret identity irresponsibly can have terrible consequences, so bear that in mind when a fellow hero has shown you their trust.

2) Innocents above all else: Before your endorsement deal for Pepsi, before your interview on Late Night.  Before your photo op or your chance to be seen with a celebrity at a Lakers game, remember why you are wearing the costume.  It is to help people.  It is to save lives and protect innocents.  If all you are about is grandstanding and mugging for the camera then people are going to catch on.  Bystanders will not trust you, other heroes will not take you seriously, and the authorities certainly will not feel compelled to give you any more help than you absolutely require.

3) Killing?  Still bad: Villains may avoid the consequences of their actions through legal incompetence.  They may escape from prison.  Their cruel and sadistic actions may make them the scum of the earth.  But killing them is wrong.  It goes beyond simple morals or ethics.  Super heroes work within the framework of the law not only because it protects their endorsements or it is convenient.  The average person must be able to trust a hero, must believe they are not some sort of trigger happy borderline sociopath with delusions of godhood who now chooses who lives and who dies?  And are you quite certain the villain you just slew was the same one who was wearing that mask last week when that tenement was burned to the ground?  There is a good reason there is a court system, to establish fact, determine truth.

And another point to consider; if you develop a reputation as a murderous vigilante, what is to stop the villains from treating you the same way?  Not all villains are sociopaths, but if they realize they are fighting one they may very well change their tune.

Of course, there are exceptions.  Captain America killed during war time and later on in a Mark Gruenwald story had to gun down terrorists with a submachine gun to save innocent lives.  But killing should be an extreme exception, not the rule.

4) Torture?  That is still bad, too: Contrary to popular belief, not all villains are evil.  Some are in it for cheap thrills, others for personal gain.  Still others may have a cause they are championing and work outside the law to accomplish it.  Whatever the reason, going around abusing and torturing them, thinking that because they are super villains then they have forfeited any and all consideration for humanity is a heartless and quite un-heroic thing to do.  The authorities frown on it and confessions and information gained from it gets thrown out of court.  Perhaps in certain circumstances where human life is on the line then it is permissable, but that takes one to the top of the slippery slope.

5) Capes are for the stupid: At one point many heroes wore capes.  Capes looked cool, they were dramatic.  They allowed a hero to hide their hands if they wished to do something surprising and it made flying heroes look majestic as they darted across the sky.  But capes are far more trouble than they are worth.  Capes get stuck in doors, are easy things for villains to get ahold of during a fight.  And they look pretentious.  Only one hero in a hundred looks good in a cape, and fewer have the ability to employ one without life threatening results.

The Vindicators           Behind The Veil