For example, editing the (long inactive) question to
- add trivial tags, like faq
- Change tags to synonymous tags, e.g. Classical Mechanics to Newtonian Mechanics
- Correct insignificant grammatical errors, e.g.
Why did the Earth cooled down
Why did the Earth cool down
- Removing substantial portions of other answers, summarizing the edit as removed crap.
Some notes on the application of site privileges
All site privileges should be used judiciously.
As a long term goal we would like to see good grammar, usage and spelling predominate on the site. However, we also don't want to see an endless stream of one-word edits. This is a major reason for the six-character minimum on suggested edits: to accustom users to the idea that edits should be generally be significant in size as well as correct in what they edit.
Other users may not want to see the stylistic feel of their work changed by another person simply because the editor has a different personal style. It doesn't need to be the way you would have done it needs to be correct and clear.
Don't start a fight over it
If someone rolls back an edit do not reinstate it. Doing so makes it about the egos of the people involved. Let it go: it does not reflect on your personal worth. If you think the edit really was necessary, flag it for moderator attention.
Don't take it personally
Someone fixing your spelling errors isn't personal. Neither is someone rolling back an edit. Nor their posting some unscientific nonsense. Again, this does not reflect on your personal worth. We have mechanisms for handing these problems without needing to get your dander up.
Don't try to make some kind of subtle statement
The tagging of questions is not a system for rating them. Nor for marking which questions are interesting and which boring. It is purely a system for categorizing the kinds of physics content each question touches on.
Neither edits nor the edit messages should be used as a place to express your opinion about a post. You rate posts for quality by voting. You rate a post's appropriateness by voting or not voting to close (assuming you have that power) or by flagging spam and offensive dreck.
This site aims to be a milieu for professional scientists, skilled and capable amateurs and those aspiring to be one. That calls for a certain amount of decorum, and certainly for grown-up behavior. If you wouldn't want your mom or the hiring committee at your next job to see, think twice before doing it.
We don't, really. People shouldn't make edits unless they represent a nontrivial improvement to the question. But note that tag changes are often nontrivial, because people use tags for filtering and also for understanding the context of a question, so it's relatively important to have accurate tags on questions.
Existing tags are chosen as they are for a reason, generally; for example, classical-mechanics is more general than newtonian-mechanics. The former encompasses Lagrangian and Hamiltonian mechanics, and is used in particular when one wants to indicate non-quantum mechanics. So even something that may look like a trivial edit, i.e. changing one of those tags to the other, often isn't. If you think you see two synonymous tags, you can ask on chat or here on meta to see if they should be merged, but there's a decent chance they are separate for a reason.
Am I really discouraged from correcting spelling and grammatical mistakes?
For example changing "tale" to "tail" is trivial in the sense that it doesn't affect the meaning of the question, but it makes a big difference to the way visitors will perceive this site. Do we really wish to encourage the stereotype that scientists are illiterate?