"And/or" is actually a fairly stupid expression, since the English words "and" or "or" aren't as exact or exclusive as this expression seems to imply. For example,

I like coconuts and steaks

doesn't necessarily mean "I like coconuts and steaks at the same time".

Here,

I can upvote an answer that satisfies me and/or mark it as accepted.

could just as well be

I can upvote an answer that satisfies me or mark it as accepted.

There are very few people, except argumentative weirdos, who will take that to mean that you can't do both of those things.

If you desperately need to emphasize that both things are possible then Noldorin has answered that in detail.

"And/or" is actually a fairly stupid expression, since the English words "and" or "or" aren't as exact or exclusive as this expression seems to imply. For example,

I like coconuts and steaks

doesn't necessarily mean "I like coconuts and steaks at the same time".

Here,

I can upvote an answer that satisfies me and/or mark it as accepted.

could just as well be

I can upvote an answer that satisfies me or mark it as accepted.

In the context of a normal piece of writing, there are very few people, except argumentative weirdos, who will take that to mean that you can't do both of those things.

If you desperately need to emphasize that both things are possible then Noldorin has answered that in detail.

"And/or" is actually a fairly stupid expression, since the English words "and" or "or" aren't as exclusive as this expression seems to imply. For example,

I like coconuts and steaks

doesn't necessarily mean "I like coconuts and steaks at the same time".

Here,

I can upvote an answer that satisfies me and/or mark it as accepted.

could just as well be

I can upvote an answer that satisfies me or mark it as accepted.

There are very few people except argumentative weirdos who will take that to mean that you can't do both of those things.

If you desperately need to emphasize that both things are possible then Noldorin has answered that in detail.

"And/or" is actually a fairly stupid expression, since the English words "and" or "or" aren't as exact or exclusive as this expression seems to imply. For example,

I like coconuts and steaks

doesn't necessarily mean "I like coconuts and steaks at the same time".

Here,

I can upvote an answer that satisfies me and/or mark it as accepted.

could just as well be

I can upvote an answer that satisfies me or mark it as accepted.

There are very few people, except argumentative weirdos, who will take that to mean that you can't do both of those things.

If you desperately need to emphasize that both things are possible then Noldorin has answered that in detail.