I need to correct something in this thread here, and that is that not all Stewart tartans are universal.

This is an important point.

Some are. But most are not.

The Hunting Stewart has always been, ever since it was developed in the 1830s, intended to be used as a universal tartan.

The Royal Stewart, according to most people, is also a universal tartan. There are some out there that beleive that this tartan should properly only be worn by the Royal Family, but if that were the case you wouldn't see it being used so widely in kilt-hire shops, on shortbread tins, men's shirts, pajamas and wrapping paper (think how carefully restricted the royal Balmoral tartan is, by comparison).

Then you have various tartans based on the Royal Stewart that one could argue, by extention, are universal. Black Stewart, Dress Stewart, Blue Stewart, Grey Stewart, Camel Stewart, et al.

But not all Stewart tartans are universal! The Old Stewart tartan is definitely a Stewart Clan tartan. Also, the various branch tartans belong distinctly to the Stewart clan; Stewart of Atholl, Stewart of Appin, Stewart of Galloway, Stuart of Bute, Stewart of Fingask, just to name a few. These are all clan tartans and cannot be regarded as universal.

Now, does that mean you have to have an established pedigree to wear these? Of course not. You can wear any tartan you like. But when you wear one of these latter tartans, you will be wearing a Stewart clan tartan, not a universal one.

To address the specific question of the Prince Charles Edward Stuart tartan, you are as free to wear that one as any other tartan. If you choose to honor Prince Charlie for whatever reason, please feel free to wear it. There are certainly no restrictions placed upon it. It would be considered a commemorative tartan for that individual (though because he was a Stewart you find it being used mostly by that clan, just as the Rob Roy tartan is used mostly by the MacGregors, and the Sir Walter Scott tartan is used mostly by the Scotts, etc.)