Learn English – Quotation Marks Around Nicknames

SHORT ANSWER: The quotation marks appear to be an attempt to claim trademark protection for a brand or tagline that may be entitled to little or no right to protection. In themselves, they do not provide that protection, but still may discourage copying by competitors.

LONG ANSWER: Trademarks include brand names, company names and taglines (slogans). The degree of distinctiveness (the ability to use a trademark to distuguish a company's goods or services) are divides into four levels:

• Generic - the common name for a good or service; not protectable (automobile, fork, hairstyling)
• Descriptive - a common attribute of a product; not protectable unless it has aquired distinctiveness, ususally through long exclusive use (TCBY - The Country's Best Yogurt)
• Suggestive - terms that do not directly describe but imply some feature; often a play on words; protectable (Sheer Elegance for stocking)
• Arbitrary or fanciful - a real word or made up term that has nothing to do with the product; highly protectable (Apple for computers and Kodak for film)

Tagline protection is similar. The more commonplace the phrase, the less protectable. Fast car would not be protectable, but Just do it! is.

There is no requirement that trademarks be in any particular typface, style or punctuation. Some trademarks usually appear in distinctive typfaces (such as Coca Cola) but many do not. There is no requirement that quotation marks be used, and they provide no automatic benefit.

Some of the examples the OP lists appear to be descriptive terms (Standard; Jiffy) that would be barred or have difficulty obtaining protection. The tag line the Cream of the Stars is a riff on numerous other slogans that claim use by celebrities. The All American Pause is a bit more unique. Both might be protectable if used over time.

The introduction of quotation marks seems to be an attempt to set off the brands and taglines and to assert a claim to their distinctive use to identify the labeled products. The quote marks by themselves don't do it. But if the marks serve to discourage competitors from using similar marks, it might result in exclusive use over time that would convey protection.

Finally, while trademarks are often registered, they are protectable even without registration (in the US). The quotes may also be an attempt to indicate that the term is claimed as a trademark even though it is not registered. Under current practice, this is more commonly done (but not required) by placing (TM) after the trademark.

FOOTNOTE: Standard as a trademark for plumbing fixtures was a registered as far back as 1923, but based its claim of protection on used dating back to 1894.

It's a matter of style. UK English tends to use single quotes whereas US tends to use double quotes. There's no additional rule for individual characters.

I don't think it's essential to use quotation marks when indicating an individual letter, but it may help for clarity. It helps when distinguishing between single-letter words and single letters, for example.