1. loan word, オーレド ボーイ、Old boy, manga (comic book)
The title of the comic book is written in katakana because its title is "old boy," an english word. Reading it in Katakana, the reader understands that the word is not Japanese. Reading characters used to for foreign words, he is primed to go into the fantasy of a world unfamiliar to his own.
2. brand name, ユニコロ, uniqlo, advertisement
-"Uniqlo is a Loan word made up by the company. It is a contraction of "unique clothing" (http://en.wikipedia.org/wiki/Uniqlo).
-"ユニコロ" is Aesthetically pleasing and simple. Every letter is square-like.
Uniqlo prides itself on its simple, high quality clothes. On the companies website, they describe themselves as "a new-style Japanese firm making good casual clothes available for all to wear....our reputation for high-quality, basic casual wear is growing steadily year by year"(Uniqlo website). The katakana characters, simple yet useful in terms of its catchy name, mimic the company's clothing style. Seeing this logo, consumers get an over all feel for the style of this company.
The textbooks may be sure to describe Katakana's proper use to maintain the integrity of its original usage, and the use of Hiragana and Kanji as is properly systematized by the language. Katakana is used so often in popular culture, even in the US to some extent, like with the UNIQLO signs, that people may mistake it for "Japanese." Teaching the language, the textbooks are sure to explicitly describe their proper purpose.
http://www.fastretailing.com/eng/ir/direction/message.html
