/r/

/r/ can refer to:

Registered trademark symbol

The registered trademark symbol (®) is a symbol that provides notice that the preceding word or symbol is a trademark or service mark that has been registered with a national trademark office. A trademark is a symbol, word, or words legally registered or established by use as representing a company or product.. Notwithstanding the symbol doesn't meet the threshold of originality to be protected by copyright because it consists only in a capital letter rounded by a simple geometric shape, in some countries it is against the law to use the registered trademark symbol for a mark that is not officially registered in any country.

Trademarks not officially registered can instead be marked with the trademark symbol ™, while unregistered service marks are marked with the service mark symbol ℠. The proper manner to display these symbols is immediately following the mark, and is commonly in superscript style but is not legally required.

Computer usage

The registered trademark character has a standardized representation in most computer systems. It is mapped in Unicode as U+00AE ® REGISTERED SIGN (HTML ® · ®). The registered trademark symbol ® is distinct, in computer representation, from the similar character U+24C7 Ⓡ CIRCLED LATIN CAPITAL LETTER R (enclosed R)

R-colored vowel

In phonetics, an r-colored or rhotic vowel (also called a retroflex vowel, vocalic r, or a rhotacized vowel) is a vowel that is modified in a way that results in a lowering in frequency of the third formant. R-colored vowels can be articulated in various ways: the tip or blade of the tongue may be turned up during at least part of the articulation of the vowel (a retroflex articulation) or the back of the tongue may be bunched. In addition, the vocal tract may often be constricted in the region of the epiglottis.

R-colored vowels are rare, occurring in less than one percent of the languages of the world. However, they occur in two of the most widely spoken languages: North American English and Mandarin Chinese. In North American English, they are found in words such as butter, nurse and, for some speakers, start. They also occur in Quebec French, in some varieties of Brazilian Portuguese and some Jutlandic dialects of Danish.

Notation

In the IPA, an r-colored vowel is indicated by a hook diacritic ( ˞) placed to the right of the regular symbol for the vowel. For example, the IPA symbol for schwa is ə, while the IPA symbol for an r-colored schwa is ə˞. This diacritic is the hook of ɚ, a symbol constructed by John Samuel Kenyon along with ᶔ by adding the retroflex hook (right hook) to ə and ɜ. Both ɚ and ɝ were proposed as IPA symbols by editors of the American Speech in 1939 to distinguish it from əɹ. The IPA adopted severals ways to transcribe r-colored vowels in its 1947 chart: the turned r ɹ; the superscript turned r əʴ, aʴ, eʴ, ɔʴ, etc.; the retroflex hook ᶕ, ᶏ, ᶒ, ᶗ, etc.; and added ɚ as a variant of ᶕ in its 1951 chart. In 1976 the retroflex hook was dropped due to insufficient usage. In 1989, after the Kiel Convention, the hook of ɚ and ɝ was adopted as a diacritic placed on the right side of the vowel symbol for r-colored vowels, e.g. [ɛ˞ o˞ ɔ˞ ə˞]. The use of the superscript turned r (əʴ) is still commonly seen.