Edited by Moeckerkalfie & Barabas:
For the next patch it will be possible to implement unique clan-standards & clan shields too, so that clans can actually carry their symbol to battle. These standards & shields will only be available to clan members in the buying menu, and will work like the ones we currently have. Requesting a clan standard and/or clan shield works the same as the banners, you need a clan thread and at least 5 members to request one.
A full set of templates for heraldry, standards and shields is now available to create custom designs. According to the rules listed further up a clan may create a number of custom designs for their respective faction of choice and commit them by sending the resources to either Barabas or me, or by uploading them in this thread.
The collection contains layered texture files in .psd format, which can be opened with photoshop or gimp.
It contains both a psd file that can be edited as well as a jpg file in case you can not use any program able to open the psd (take note that due to the restrictions of jpg files it doesn't contain the fabric overlays). You can test your banner by converting it into a .dds file and placing it in the folder Vikingr/Modules/Vikingr/Textures under the name banners_g.dds.
This way it will replace the duplicate version of the green hare banner, created by Hengwulf.
A banner added like this is only visible to those who use this texture: It will not change for the other players and still show as the green hare. If you wish to have the banner visible for everyone it is best added into a patch, so that if you fulfill the requirements you should just send me (Moeckerkalfie) a PM or e-mail about it.