I created a magical shield. It's tied to the character's backstory, has interesting quirks and features, the most important being it is made of a custom material (ie not wood or iron). Irritatingly however, the description of the item auto-includes this line: 

"A shield is made from wood or metal and is carried in one hand. Wielding a shield increases your Armor Class by 2. You can benefit from only one shield at a time."

While I appreciate the rules clarifications, I don't appreciate the flavour of the materials. It's especially egregious if I spend a couple of lines describing the custom material, only to then have to read that a shield is made from wood or metal. I'd think we'd want to not have "flavour text" co-mingled with rules text wrt auto-includes.

Is there a workaround? I thought about not selecting "armor/shield" as the type, and instead choosing "item" and then writing everything in manually.

Thanks in advance. 

I don't think there is a way to exclude that text. I recommend ignoring that it is even there.