As an old story goes:

The little boy's mother was going off to the market. She worried about her son, who was always up to some mischief. She sternly admonished him, "Be good. Don't get into trouble. Don't eat all the chocolate. Don't spill all the milk. Don't throw stones at the cow. Don't fall down the well." The boy had done all of these things on previous market days. Hoping to head off new trouble, she added, "And don't stuff beans up your nose!" This was a new idea for the boy, who promptly tried it out.

In our zeal to head off others' unwise actions, we may put forth ideas they have not entertained before. As the popular saying goes, "don't give 'em any ideas".

In other words, don't give potential vandals examples of how to cause disruption. This may will actually tempt them to do it.^{[Note 1]}

Perhaps the boy's mother could have said the following instead:

Keep your nose clean!

Throughout the 19 years this essay has existed, it has adopted a different meaning to that suggested by the above text. There are many areas of the encyclopedia that rely on, or benefit from, some level of security through obscurity, such as WP:SPI. For this reason—citing this essay—specific cases and abuse mitigation are often left undiscussed on-wiki. An essay explaining this in more detail is Wikipedia:There's a reason you don't know.

• Special:PrefixIndex/Wikipedia:Don't
• Wikipedia:Avoid instruction creep
• Wikipedia:Do not disrupt Wikipedia to illustrate a point
• Wikipedia:Don't delete the main page
• Wikipedia:Don't stuff beans up the developers' noses
• Wikipedia:No climbing the Reichstag dressed as Spider-Man
• A counterpoint to this essay
• Every time someone clicks this link, an innocent kitten, a person, a cow, a bat, a frog, a whale, a dolphin, an axolotl, and a tiger die. (not necessarily in that order)

• Negative suggestion
• "Beans in My Ears," a 1960s song
• Reactance (psychology)
• Reverse psychology
• Security through obscurity
• Streisand effect
• Ostension
• Pandora's box