June is Pride Month, and the most visible manifestation of this celebration of the gay community is the rainbow–in particular, the Rainbow Flag designed by Gilbert Baker in 1978. In recent Junes, the flag has gone mainstream as companies such as IBM have rolled out rainbow versions of their logos to honor (or co-opt) the Pride movement.

The use of rainbows in commercial symbolism is a relatively recent phenomenon. Analysis of United States Patent and Trademark Office data (see below) shows that, prior to the late 1970’s, very few American logos featured rainbows. Saul Bass’s 1972 United Way logo was a notable exception, and Rob Janoff’s 1977 Apple mark, with its famously out-of-order colors, helped bolster the trend. In 1978, as Baker sewed his first flag and Robin Williams’s Mork from Ork first graced American airwaves with his rainbow suspenders, the popularity of rainbow logos suddenly spiked, and remained high throughout the 1980’s.

Early uses of rainbow colors in logos often specifically emphasized color as a product feature: NBC’s peacock highlighted the network’s color broadcasts, and Apple’s logo touted the Apple II computer’s color graphics capabilities. But the positivity and cheerfulness communicated by the rainbow make it an attractive choice as a general design element.

Of course, the rainbow’s appeal is based in color; designers’ early aversion to rainbows was likely due to the fact that logos often had to be presented in black-and-white media such as newspapers and fax. Throughout the 1980’s, this black-and-white world was still a reality, so rainbow logos had to be readable as rainbows even without color; hence, the familiar semicircular shape.

But in more recent years, as technological advances have brought color to almost every medium, the spirit of the rainbow can be communicated through its colors without the need for its explicit shape. Consequently, the use of rainbows as logo design elements has fallen back almost to its pre-1970’s level, while the use of rainbow colors in logos has taken off.

Today’s rainbow-colored logos reflect the joy and optimism inherent in the rainbow in a multitude of new expressions.

Does your local craft brewery’s logo helpfully inform you that the business was “Est. 2016”? Logos declaring the year that a company was established seem to be everywhere recently. In particular, businesses seeking to adopt a hipster aesthetic appear to append an “est.” to their logos just as often as they use crossed objects or mustaches in their marks. What accounts for the prevalence of this visual quirk?

Analysis of United States Patent and Trademark Office data confirms that “est.” and other abbreviations for “established” have been appearing in trademarks much more often in recent years–in fact, in terms of percentages, 19 times more often this year than in 1980. The related term “since” has also enjoyed increased popularity among trademarks, but was no match for “est.,” which surpassed it in use in 2015.

Among these “est.” trademarks filed this decade, the most common abbreviation used is “est.” itself (with or without the period), appearing in 91.7 percent of such marks. Less often used, accounting for 8 percent of these trademarks, is “estd.” and its variant “est’d.,” which, perhaps owing to their rarity, seem to project more gravitas, particularly in the typographic variation in which the “D” is made smaller and placed above the period (see the Guinness and Coors Light logos above). Only 0.3 percent of these marks dare to go with the “estab.” abbreviation.

“Est.” seems to function in trademarks in two ways. First, in a basic sense, it seeks to use the business’s longevity as a proxy for its trustworthiness and reliability. When a logo notes that a restaurant was “est. 2015,” though, this function disappears.

Among trademarks filed in 2017 to date, the average year that follows the “est.” is 1988, just 29 years ago. In comparison, the average year after the “est.” in trademarks filed in 2000 was 1939, or 61 years earlier. Clearly, the longevity-signalling function of “est.” is becoming less important today.

The second way that “est.” works in trademarks is to evoke the logos of the past. There is a sense that “est.” was used a lot in old trademarks; the marks below, all from the first half of the last century, exemplify this usage. Including “est.” in today’s logos is an attempt to imbue them with a vintage feel that often aligns with the aforementioned hipster look.

Digging back further into USPTO records, we can see that “est.” was indeed used much more often in the first half of the twentieth century than in the second half. Interestingly, though, the rate of use of “est.” during this decade has surpassed that of the 1910’s!

Today’s use of “est.” in trademarks is doubly ironic. Promoting a business as “est. 2017” in 2017 borders on ridiculousness. And using “est.” as a symbol of old-timeyness more often than it was used during those actual old times is nearly as silly. What is not clear, though, is how much of this irony is intentional.

When it comes to logos, it’s still a man’s world. Since 2000, male figures in US logos have outnumbered female figures by 3 to 1. A look back at logo design trends over the past 60 years shows that this is not a new state of affairs.

Percentage of new logos featuring male and female design elements

As the graph above shows, there has not been much change in the relative percentage of logos featuring males and females since 1950. Perhaps most notable here is the slight overall decline in male logos, which may be the result of the contemporary trend of designers using what Michael Bierut calls “neutered sprites” to represent people in general, when in the past they might have gone with more graphically elaborate male figures. (Gender-neutral figures such as Bierut’s sprites are not included in this analysis.)

Percentage of new “gendered” logos featuring male or female design elements

We see above that this ratio of male to female logos has not changed much over the years; again, it appears that 3 out of 4 new logos that have some gendered element are male as opposed to female, with a slight decline in that ratio over time that may be attributable to the “sprite effect” discussed above.

 Percentage of “gendered” logos featuring male or female design elements, by industry

Across all years, 76 percent of gendered logos feature male design elements, while 24 percent contain females. There is variation from these averages across industries, however. Logos from industrial categories such as firearms, construction, and telecommunications are more likely to include male figures, while among logos related to clothing, pharmaceuticals, and alcohol, there is a more pronounced tendency toward featuring females.

Will the gender gap in logos ever be closed? There certainly do not seem to be a lot more women appearing in logos. Designers seeking to avoid giving off an impression of sexism seem more likely to use a genderless figure, rather than a female one, to represent a generic person. If women are to catch up to men in logos, it will probably be due to more male figures being replaced by “neutered sprites,” not to any increase in the use of female design elements.

Now that twenty-three U.S. states have legalized marijuana in some form, the drug’s potential in the legitimate business world is quickly being recognized. The legal sale of marijuana is now being bolstered by the same marketing and branding techniques used to sell soap and toothpaste. But a quick glance at the current practice of marijuana branding reveals that it is clearly still in its infancy.

In a 2015 interview with Fortune magazine, investor Brendan Kennedy, a backer of the Marley Natural marijuana brand, complained that in the marijuana business, “Everything is named ‘canna-something’ or ‘mari-something,’ with a green and black logo and pot leaves.” Indeed, analysis of United States Patent and Trademark Office records shows that 44 percent of logos registered as trademarks for marijuana-related businesses feature the familiar cannabis leaf.

As a result, marijuana branding is visually indistinct. Even when the heavy hitters of branding and design have been brought in, avoiding the easy design solution represented by the leaf has proven difficult. For instance, the mark for Snoop Dogg’s high-profile Leafs by Snoop marijuana line, designed by Pentagram’s Emily Oberman, while visually arresting, is simply a depiction of a pot leaf. And even the Heckler Associates-designed logo for Kennedy’s Marley Natural featured the leaves as a secondary design element at the time of his quote (although they have been recently dropped, with the focus now squarely on the brand’s lion symbol).

USPTO records show that the first U.S. marijuana leaf logo trademark was filed in 2004, and the years since have seen an explosion in the symbols. By 2015, over 1 in 500 new U.S. logos featured a cannabis leaf.

The problem with the leaf as a symbolic element in a marijuana business logo is that it is so commonly used that it acts as a symbol of merely the general category, rather than of the specific brand. Such visual clichés can be found in many fields, stemming from tradition (such as the use of striped poles as symbols for barbers) or obviousness (like dentists employing tooth logos). The graph below shows that the use of cannabis leaves in marijuana logos has reached a particularly heightened level of cliché.

This is fine when the category is more important than the brand. If you need a quick haircut or your molar is killing you, you’ll look for the first striped pole or tooth logo you can find. Because legal pot is still a novelty, the leaf itself is enough to attract business. But as marijuana becomes legally available on a more widespread basis, its branding is going to have to move beyond the generic leaf to incorporate more distinctive visual elements.

With Valentine’s Day upon us, hearts are everywhere, and they seem especially prevalent these days in logos and other visual symbols. Art historian Martin Kemp, in his 2012 book Christ to Coke: How Image Becomes Icon, outlines the fascinating and complex use of the “heart-shape” over history, from early anatomical depictions of the organ to the symmetrical symbol that we are familiar with today. “It is,” Kemp writes, “a shape that is appealing in its simple yet seductive rhythm, and once seen it is difficult to forget. It is like the melody of a great pop song.”

This appeal of the shape, along with its positive connotations of love and life, have long made it a popular design element. Oscar-Edmond Ris-Paquot’s 1893 Dictionnaire Encyclopédique des Marques & Monogrammes is full of heart marks used over the previous several centuries.

By the early twentieth century, there were warnings that hearts made for poor trademarks and logos due to overuse and subsequent lack of distinctiveness. Glen Buck, in his 1916 book Trademark Power: An Expedition Into An Unprobed and Inviting Wilderness, wrote “Common and familiar forms do not usually make good trademarks, for they lack distinction. The circle, the square, the crescent, the star, the diamond, the heart, the oval, the shield, the cross, all have long ago been usurped and are burdened with significance.” And yet the register of the United States Patent and Trademark Office continued to fill up with heart trademarks.

The use of hearts in logos was further boosted in 1977 with the introduction of Milton Glaser’s massively popular “I ♥ NY” mark, which quickly inspired a host of imitators. As of this writing, United States Patent and Trademark Office records show that there are 1,407 “I ♥” trademarks registered.

In recent years, designers have realized the potential of the simple heart shape to be used in increasingly clever and elaborate ways. One such application is to turn the heart into a letter of the alphabet for use within a wordmark. The versatile heart shape may take the form of, at a minimum, the letters a, b, c m, o, u, v, and y. A 2013 Emblemetric analysis showed that hearts are especially popular elements of “frankenmarks” (wordmarks featuring a pictorial element replacing a letter), appearing in 3.54 percent of such logos.

The popularity of the heart, though, often means that appealing visual uses of the shape have been done before. Designers seeking to create a logo that employs two fingerprints to make a heart, or two hands to form a heart, or a handshake as a heart, or a heart within a pawprint should perhaps reconsider.

The ubiquity of hearts has continued in recent years, as companies such as Southwest Airlines, CVS Health, Airbnb, and Thomas Cook have unveiled new heart logos. Hearts play an important role in indicating positivity on social media sites such as Instagram and Periscope. Late last year, Twitter famously changed its starred “favorites” to heart-denoted “likes,” and detached the symbol from its traditional meanings, declaring that it could represent anything from “wow” to “high five” to “stay strong.” Hearts are consistently among the most commonly-used emoji, and can even be expressed in plain text form as “<3”.

Analysis of United States Patent and Trademark Office data reveals the increasing use of hearts in logos over time. Heart logos as a percentage of all US logos peaked in 1989 at 1.74 percent, then declined to 0.95 percent in 2000. Starting in 2001, heart marks took off again, reaching 2.25 percent of all logos in 2013.

The sharp increase between 2001 and 2013 may be attributable to any number of causes that lie beyond our understanding. But it is worth considering the possible impact of the September 11, 2001 terrorist attacks on the American psyche and, subsequently, American logo design.

Zooming in to examine the data by month, we can see that the period following September 2001 brought several spikes in heart logos as the trend began to move upward. Of course, the timing of the filing of trademarks for businesses and products is dependent upon many factors. I don’t find it unreasonable, however, to speculate that in the wake of September 11, Americans’ yearning for love and healing was ultimately manifested in the heart-shaped logos that surround us today.

The horrific June massacre of nine African-American churchgoers in Charleston, South Carolina by a gunman with a fondness for the Confederate battle flag galvanized public opinion against the symbol, resulting in its removal from the state’s capitol grounds after years of controversy. The perception of the flag as symbolic of racist hate seemed to gain traction against the competing view of it as a benign emblem of Southern heritage.

From a commercial standpoint, this was a debate that appears to have long since ended. The Confederate flag’s use as a logo design element by US companies has dwindled to a low level, according to an analysis of United States Patent and Trademark Office records. Currently, there appear to be just eighteen active, or “live,” US trademarks that feature Confederate flag imagery (by contrast, there are 1,938 active marks featuring the US flag). Tracking these flag logos over time is difficult, because USPTO records do not include marks that “died” prior to the 1980’s. But of the 83 marks that can be identified in the USPTO database, most were owned by companies in the South, as shown on the map below, and 78 percent are no longer active, or dead.

Of course, not all businesses officially register their marks with the USPTO, so there are other Confederate flag logos in use, including one that an Iowa bagged-ice company has said it will not abandon. But use of the flag in larger, mainstream contexts appears to have vanished.

Older USPTO records show the flag in logos for products like shrimp (“Taste of Dixie,” 1991), mops (“Dixie Dust Control,” 1981), boats (“Dixieland Marine,” 1981), and blue jeans (“Rebel,” 1984). But these marks are no longer active, just as, over the years, the Six Flags amusement park lowered the battle flag, the NASCAR Southern 500 race dropped it from its logo, and the country band Alabama stopped using the flag, which had adorned four of its album covers.

Today, use of the Confederate flag in logos is confined to a narrow group of business types. Of the 49 Confederate flag marks filed since 2000, over half (55%) represent clothing lines, such as the purveyors of lifestyle or novelty t-shirts seen below.

Interestingly, some of these marks have attempted to co-opt the flag as a symbol of African-American identity, in the manner of Kanye West.

Eighteen percent present the flag in an historical context, often in conjunction with the US flag.

Sixteen percent are associated with motorcycle clubs, where the “rebel” aspect of the flag’s meaning is still appreciated.

The meaning of symbols, including words and logos, can change over time. If public opinion continues to turn against the Confederate flag, it is not inconceivable that logos featuring it might someday be denied trademark protection, in much the same way that National Football League’s Washington team has seen its “Redskins” trademark canceled.