I’m sure that the phrase “Any port in a storm” refers to a maritime crisis solution, and thus the P in port isn’t capitalized.

But it is capitalized when it comes to the after-dinner dessert wine that seems most apropos during storms or any cold weather.

And although many domestic wineries make a Port-styled wine, that name can no longer be used, even in describing the wine, on a wine label. Portugal’s most famous wine comes (somewhat confusingly) from Oporto, and thus the Anglicized version is a place-name, Porto, that’s protected, and may not be used by a non-Portuguese winery, as once was common in the United States.

Many domestic wineries that make a Port-styled dessert wine call them either by a generic name or use a proprietary designation, such as the clever name adopted years ago by wine make Andy Quady, Starboard. (The opposite of Port?)

Port and Champagne are the world’s two most carefully protected place-name wines in part because both regions control their own financial destinies by careful choice of how they “declare” a vintage for their top-of-the-line wines.

Both vintage Champagne and vintage Port, the before-dinner and after-dinner wines of a great feast, are seen as the highest vinous art forms in the sparkling and fortified dessert wine categories, respectively. And as such the wineries of the two districts are extremely careful not to declare a vintage too often.

The same producer rarely declares a vintage two years in a row, for example, or twice in a three-year period. So a vintage Champagne or a Vintage Port is a special purchase and, thus, typically significantly pricier than a typical non-vintage choice.

Thus are the volumes of the very best wines kept under rigid control, assuring that prices for the very best will never be at the mercy of gray- or black-market forces that can erode pricing for all products from the two regions, including related non-vintage wines.

But with Port, the story is far more complicated, partly because with Port, much of the best improves with age, in some cases, a lot of age!

So there is very brisk aftermarket for vintage Port, not as much for Champagne. The aftermarket for Champagne is small.

Also, Port has many more products, including Tawny Port, Ruby Port, late-bottled vintage Port, single-quinta (estate) Port, and many more.

Ruby Ports ($12 to $20) tend to be fruity and a bit simpler in overall flavors and sell for less than Tawny Ports.

Tawny Ports ($15 to $35) are popular since they are aged for about a decade in barrels and have more depth. A few tawnies are aged even longer and can be expensive. A top 20-year Tawny from a good house (Graham, Dow, Warre, Sandeman) can sell for $30 to $40, but delivers a lot of complexity.

The best Ports, in the view of some collectors, are vintage-dated. When they are from a great house and a great vintage, (such as 2005, 2007, or 2011), the wines are best at 20 to 40 years of age! Or older. (We still have a few bottles left from 1963, which are considered by Port lovers still too young to drink!)

LBV (Late-Bottled Vintage) is not a true Vintage Port, but can be a special treat. It spends more time in cask than do true vintage Ports, and can be enjoyed a lot sooner than vintage Port.

Colheita Port is an odd category in which the vintage is listed on the label, but where the wine was aged in cask for years like a Tawny. However, it is from a single year that wasn’t quite good enough to declare as a vintage.

Dan Dawson at Back Room Wines in Napa says one of his most popular Ports is the 2005 Quinta do Infantado, which is a Colheita ($39).

At Santa Rosa’s Bottle Barn, the 2002 Smith-Woodhouse LBV ($26.99) is extremely popular.

Wine of the Week: NV Warre’s Otima 20-year-old Tawny Port ($35/500-ml): The fascinating aroma features candied orange peel, molasses, caramel, and a decadent note of burnt hazelnuts. The mid-palate isn’t as sweet as most Ruby Ports, and the wine offers a great contrast for sharp cheeses, or a match for crème brulée. This wine is stylishly packaged and would be a special holiday gift.

Dan Berger lives in Sonoma County, where he publishes “Vintage Experiences,” a weekly wine newsletter. Write to him at winenut@gmail.com.