Queen Elizabeth II is a strict woman. She has plenty of royal fashion rules, even for the most minor of accessories. The monarch apparently is very specific about her hats.

In “Our Rainbow Queen” by Sali Hughes, the sovereign is revealed to have many requirements about length and size, far beyond just the fit. First, they must be noticeable. “Hats must be tall enough to be seen,” Hughes writes.

However, the Queen doesn’t want to have to fuss too much over her headpiece, so she needs them “short enough to remain secure in a car.”

Hughes reveals the brims are the biggest issue. “She is particular about brims, which must be narrow enough for crowds to catch a glimpse of the monarch … and for herself to see clearly, particularly when racing is involved,” the author reveals.

Hats, however, are daytime wear. Just as diamonds are never to be worn before 6 p.m., hats are not to be donned after that time. “The Queen is rarely seen without hats before 6 p.m., when women traditionally changed for dinner,” Hughes writes.

The Queen even has rules about eating in hats. Don’t expect to see her munching on snacks when she has her head covered. “One may eat in a tiara, but never—not even canapés or finger foods—in a hat,” according to the book.

The late Philip Somerville revealed that he at one point designed 40 to 50 hats per year for the Queen, who likes to wear the pieces multiple times. “People say, 'What does she do with all those hats?’ Wear them out, I say. They get damaged and they wear out. She’d possibly wear hats at least 10 times, and that’s a long time. Most people would only buy a hat and wear it once and then they put it away in a box,” he said, according to the Telegraph.

Occasionally, she opts for a headscarf instead of a hat, which is better suited to windy days. Luckily, she has quite a selection. It is believed that the Queen has thousands of scarfs, many of which are designed by Hermès.

Queen Elizabeth II is also strict about what’s in her handbag.

Queen Elizabeth, Kate Middleton
Queen Elizabeth II and Kate Middleton, Duchess of Cambridge, at Kings Cross Station in London in 2012. Reuters