Trouble with &&'s

Well, in addition to my other problem, I've got this one. Now these are just warnings and it still compiles, but to say the least they are annoying.

space.c: 10744: warning: suggest parentheses around && within ||

I know enough to tell what its saying, on line 10744 is the warning in space.c. So here is the section of code it seems to have trouble with:

if (arg1 != "ST-A1" || arg1 != "MID-C1" && !str_cmp("TAC",ch->pcdata->clan->name) )
{
send_to_char("You cannot order that!\n", ch );
send_to_char("Consult HELP TACMODELS\n\r, ch );
return;
}

Previous code checks to make sure they have a clan and such, and previous code does other checks, so its not a problem with something such as they don't have a clan or something.

Arg1 is defined as char and to me this seems like it should work, yet it still doesn't like it. Well, anyways, I was just wondering how I would rearange the if statement so that it wouldn't have the warning.

Thanks for any and all help.

It's just rather vague to the compiler. Let's call the three things you want to test A, B, and C. The way you have it, it's something like:
A or B and C

That could mean either
A or (combination of B and C)

or

(either A or B) and C

I believe that you can simply add parenthesis around the ones you want to group. So for the first case where it was either A or the combination of both B and C, you would do:
A || (B && C)

The other one should look something like:
(A || B) && C

I'm not 100% sure on this though. I usually try to rewrite it and just put one if inside of another.

It's just looking for this:

if ((arg1 != "ST-A1" || arg1 != "MID-C1") && !str_cmp("TAC",ch->pcdata->clan->name) )

The code would likely work without them in this case as the compilers default action would do what I believe you intended it to do. But, the compiler is simply asking you to clarify the logical statement you presented.

Thanks :)