MicrostockGroup

It's getting ridiculous and is killing the enjoyment of taking photographs.

are the IS rejected shots being accepted by SS ?

Okay. I will try my IS rejected photos in SS the.. who knows they might get selected.

Oh by then they will all be "old" files and go to the back. (just kidding!) 

I uploaded a shot yesterday that I figured had less than a 20% chance of getting accepted. It has shadows! (oh no, the Sun casts a shadow...) Got the accepted email this morning. Now if it sells, that's even better!

From http://home.nps.gov/applications/digest/permits.cfm?urlarea=permits

The National Park Service permits commercial filming and still photography when it is consistent with the park’s mission and will not harm the resource or interfere with the visitor experience.

When is a permit needed?
All commercial filming activities taking place within a unit of the National Park system require a permit. Commercial filming includes capturing a moving image on film and video as well as sound recordings.

Still photographers require a permit when
1.      the activity takes place at location(s) where or when members of the public are generally not allowed; or
2.      the activity uses model(s), sets(s), or prop(s) that are not a part of the location’s natural or cultural resources or administrative facilities; or
3.      Park would incur additional administrative costs to monitor the activity.

So it seems to me that unless you're shooting models or bringing props, commercial photography is allowed, and without a permit.

Just can't wait for the answer on this one. You are correct, it's free to shoot, we own those parks, as long as none of the things KB pointed out are going on.

Yes you discovered part of it. Don't put National Park in the description and they might get accepted. Someone in review land may be confusing the National Trust and Heritage of the UK that claim to own rights to almost everything, including a mountain in Australia.

Yes we can. You need to know that if a company doesn't defend and protect their trademark, it potentially becomes public domain and generic. One of the most aggressive is Coke!

They go to places that sell other products (usually syrup dispensers) and order a "Coke" is they get a Royal Crown, Pepsi, or something else brown cola, they slap a notice on them. Usually they go to small shops and places that are never going to go to court, and then when the retailer admits to their error and promise not to do it again, Coke drops the lawsuit. This shows the courts that they are defending their Trademark.

The reason Ford came out against the use of their images, is they are defending and protecting their copyrights, designs and trademark.

A trademark is said to be genericized when it began as distinctive but has changed in meaning to become generic. Some examples: Aspirin, Butterscotch, Escalator, Kerosene,Thermos, Yo-yo, Zipper.

OK so we know it's just some green and yellow, but it's actually the specific green, not Any Green tractor. (that doesn't mean the reviewer is trained on this legal point)

Many times you can use an image of something and sell it, but you can't use the name of the company in the keywords or description.

Gas Lighter may get through, but if you use Zippo, they should reject it. Oh I hope I'm not giving the agencies more ideas? You can't use brand names in keywords or descriptions. Don't bother.

On the other hand a green and yellow tractor in the distance of a photo, is not the subject and shouldn't be cause for rejection? Oh well, here we are again. If they would give a specific reason on the rejection, we'd know?

Absolutely not, it's their specific green with their specific yellow:
http://www.deere.com/wps/dcom/en_US/footer/legal.page?

 yep, that quoted text was familiar -- i remember now specifically looking at the NP site some years ago when I was planning to use some images in an online Civil War  game I was designing.  All my NP images in the batch i mentioned easily meet the standard

re including 'NP' in the description i've always seen that as a tradeoff - lighting some dim, but wrong, memory of a reviewer - versus helping buyers  who are looking for site specific images.  eg just sold a coupla editorial images of the  Steamboat Cowboy Downhill where 'skiing steamboat' was the search used

That would be accepted by SS from some individuals.