I don't quite know what category this belongs in:

[gor80]

funny, as if someone is smoking, but there is too little detail

[gildedfool]

I like the shadow the trail makes on the underside of the clouds.

[gmans]

The category would be sky writing and back slash, makes a interesting photo.

[Na Horuk]

Very nice, I've never seen a shadow cast from one of those! Really makes the sky seem 3D, when we are mostly used to seeing it as "flat"

[alfa75ts]

I've never seen a shadow cast from one of those!

Yes, it was taken just after dawn so the sun was under both, quite unusual.

[phoenixvision]

This should be in every category...can't believe how many people are unaware of the extent to which chemtrails and cloudseeding are manipulating the weather...I work as a wedding photographer, and I can't tell you how many photos I have taken with chemtrail backdrops.....This is one of the most pronounced and thickest I have seen...good capture...