The Queen is not a fan of wedges — no surprises there. A Vanity Fair source once revealed that Queen Elizabeth II wasn't fond of some of Kate Middleton's footwear and as long as she's in the vicinity, there will not be a wedge in sight at a royal wedding.

A stylish but comfy spring/summer shoe, you'd likely spot tons of wedges at stateside ceremonies. But the Queen's disdain for the heel makes for a quirky rule that royal wedding guests are always wise to follow.

A surefire way to find yourself on the Queen's sh-t list is to not wear tights. So, it's safe to say that the women in attendance always have on pantyhose, even if they're in a sheer, barely there nude. It's definitely not the strangest rule of all, considering a royal wedding is such a classy affair, but it's still pretty strict.

If you weren't hip to royal fashion, elaborate hats are a thing, especially when it comes to weddings. And there likely will be no shortage of embellished, structural and over-the-top hats at the upcoming ceremony.

In fact, Prince Harry and Meghan Markle's wedding invitations stated day dresses with hats were required. So, expect to see some pretty strong hat game at their royal wedding. The bigger the fascinator, the better, as festive headwear is an expression of joy directed toward the marrying couple.

If guests ever thought about jazzing their fingers up with the season's brightest, boldest "it" shades, they can forget about it. Neutral manis are the only way to go for a wedding ceremony, as natural-looking nails are required for official royal events.

There is never talks of breaking out a snazzy LBD for such a big day. Often a hue associated with mourning, black is highly discouraged for royal wedding attire. Instead, guests should opt for bright hues. After all, this is a celebration of love.

Bearing arms? It simply isn't done when it comes to a royal wedding. At such a conservative event, guests are expected to wear dresses that leave their shoulders covered. On that note, there shouldn't be any cutouts or other skin-showing details on garments, either.

Speaking of appropriate dresses, the length of the garment is equally important. Dresses should always be tea length, hit below the knee, or if not, just ever so slightly above.

It's hard to imagine enjoying warm weather without breaking out a sandal. As strange as it may sound, that's exactly the kind of the thing that's not allowed during royal wedding day festivities.

No footwear other than a closed-toe shoes is acceptable. So, it turns out wedges aren't the only forbidden heel.

When it comes to accessories, small handbags are the way to go. That a large tote or purse like the Strathberry handbag Markle wore that broke royal protocol is an absolute no-no.

As per Markle's wedding invitations, morning coats and lounge suits (which are still formal, contrary to their name) are required attire for male guests.

However, if appropriate, men are encouraged to wear Military uniforms. Hence Prince William wearing a uniform to his wedding and Prince Harry likely following in his brother's footsteps by doing the same.

As if navy or tan shoes don't come in formal dress shoe options, male guests are required to wear black footwear — and those puppies better be polished. It's odd that men are given such a strict shoe rule, but there's no denying that you can never go wrong with basic black. 

Despite the strange requirements that have been passed on for hundreds of years, upcoming royal wedding fashion is going to be a must-see. All of the fancy hats alone is going to make this one interesting fashion affair.