You may not use multiple accounts to post trades if it is all your own inventory.

The only common exception would be if they were expired crates that must be kept on an alt account, and you would need to state that they were on an alt account.

Please cite the exact rule for this. You're wrong as far as I can see, Currier Bell.

On which count? I know for a fact that alternate accounts are not allowed. The gray area around expired items is the only time that alts have been allowed, and I wouldn't give a guarantee that they're totally okay to post with. The rules are in place to disallow one person having an advantage in people seeing their trades, (no relists, no autobump scripts, etc.), and using alts definitely falls into this category, else there would be no reason to put out trade limits and 30 minute waits on bumps.

Also, the rules are not all inclusive and can never be. Just read the bottom of the rules page:

"Note: Most rules are common sense and it would therefore be impossible to list all the things you could do to get yourself banned. This page is not acting as a complete list of bannable offenses — it instead aims to clear up some confusion about those rules that may not be obvious. All moderators and admins have the power to close trades as they see fit (with reason, of course). No ranks exempt you from the site rules."