Wikipedia:Don't be a smartypants

Look at the two bullet points above. They mean the same thing: Most people won't understand hard-to-understand words, so in order for them to understand you, don't use those words. However, the second version is significantly more difficult to understand than the first version because it uses more advanced vocabulary. Not everyone knows that omniscient means all-knowing, that technocrat means smartypants or user of overly technical language, or the definitions of about half of a dozen other words in the second bullet point. Therefore, the first bullet point is better as it is understandable by more Wikipedia users. This can also be applied to other scenarios in Wikipedia, not just summaries. If you made an edit request asking someone who can edit the article in question to "relocate the penultimate paragraph of the section concerning matrimony to tertiary position of the aforementioned section", a significantly lower percentage of editors with the necessary access level will know what you want them to do than if you had typed "move the second-to-last paragraph of the section about marriage rituals to between the second and third paragraphs", so your request would be less likely to be executed.

This policy can be applied to more than style of prose : If you assume that things that are easy for you to understand, whether vocabulary and terminology, measurements in unfamiliar units, general relativity, macroeconomics, or something else, should also be easy for others to understand, you are likely to: None of those are desirable. Therefore, do not assume that everyone else knows everything that you do. Also, do not criticize, make fun of, tease, chastise, ridicule, etc. anyone for simply not knowing everything that you do. Do not treat everything as obvious, and do not be overly witty, smart-alecky, or clever, as that is annoying and unfair to everyone else.
 * 1) Not be understood
 * 2) Cause confusion
 * 3) Discourage others from wanting to work with you

If you encounter someone else who is violating this essay and using overly technical language, do not link to this essay dozens of times and threaten to call an admin. Instead, calmly ask the user to explain what they meant using simpler terms. It will also be helpful for you to explain exactly which parts are confusing. Keep in mind that many users may have different backgrounds from you (and most likely do), so their perceptions of what is or isn't common knowledge may be significantly different from yours. Accept this, and also be aware of it when you communicate with others. When in doubt over whether or not something is obvious or easily understood, add a clarification to be on the safe side.