Preppy style likes to think of itself as essentially immutable. As the Official Preppy Handbook once suggested, “Preppies wear clothes for twenty-five years and no one can tell the difference.”

But a Prep’s wardrobe is not immune to the vicissitudes of fashion. While many items from Prep’s past would look perfectly at home in the modern closet (a blazer from 1957, a Shetland sweater from 1981 or a tartan wrap skirt of just about any vintage), others would just as easily appear dated, with odd cuts, out of place hemlines and gaudy prints.

This got us to thinking: What clothing, now considered largely classic in the pantheon of Prep clothing, was left out of the Official Preppy Handbook, either by omission or because that clothing had yet to be elevated to the ranks of sartorial classics? Just how much has Prep changed since that first true attempt to chronicle its stylistic dimensions?

Here are our choices. For those of you so inclined, we invite you to weigh in with your thoughts in the comments section.

1. Riding Boots

Yes, the Handbook did insinuate that  certain elements of a riding wardrobe could be appropriated for everyday wear. But it gave notoriously scant attention to the specifics. In recent years, riding boots have become one of the bedrock elements of the female Prep’s wardrobe. Owing to its strong vaquero tradition, Spain continues to make some of the best riding boots around.

2. Rugby Shirts

Had the Handbook been published a few years later, it would likely have made a nod to the venerable rugby shirt. While the rugby shirt had made incursions into college campuses in the United States as early as the 1960s, it’s apotheosis did not occur until a few years after the Handbook was published. Since then, it has come in and out of fashion, but it remains a Prep classic.

3. Quilted Jackets

It’s understandable that the quilted jacket would not merit a mention in the Handbook. After all, the jacket was invented in 1965–in England, by American ex-patriot Steve Guylas–only 15 years before the Handbook was published–a blink of an eye in Prep time. The Official Sloane Ranger Handbook, published two years later, did feature the waistcoat version of the quilted jacket, but it remained an essentially British flavor for several years after that. Eventually, the jacket began to insinuate itself across the pond where it was adopted by Anglophiles and those with a passion for country pursuits.

4. Palm Beach/Jack Rogers Sandals

How the much more prosaic Bernardo sandals finagled their way into the Handbook, where the Palm Beach sandals were left out is a mystery. Their provenance is impeccable. Jackie Kennedy picked up a pair of similar sandals on vacation in Europe. She contracted to have a pair made by a Palm Beach artisan, the design of which was eventually copied by Jack Rogers. Those in the know favor the authentic Palm Beach Sandals over the Jack Rogers versions–not only because they’re constructed to a much higher standard but also because they’re still made in the United States.

5. Breton Shirts

At the time the Handbook was published, the Breton shirt (also known as the French fisherman’s shirt) had not yet shed its association with the bohemian crowd. Owing to the Prep’s affinity for nautical pursuits, the Breton shirt was a natural addition to the pantheon of classic clothing. The authentic models are made in France, although Columbia Knit and Save Khaki both offer American made versions.

6. Seersucker for Women

Seersucker for men garnered two mentions in the Handbook. For women? Nothing. Nada. Zip. Yet, for Prep’s southern partisans, seersucker is the ur-fabric for summer wear. It can be found in dresses, skirts, shorts, beach wraps and blouses. Jolie and Elizabeth and Lauren James are two of the leading American producers of women’s seersucker clothing.