Wrong Diacritics with Pinyin

Dear lazyweb,

I am looking for examples of bad Pinyin where invalid diacritics are being used.

I have two already for the third tone, but I am curious if other tones also see similar errors.

  1. Xiàndài Hànyû Dàcídiân (Circumflex)
  2. Wŏ huì shuō yìdiănr (Breve)

Possibly letter ü experiences similar difficulties, though I'm not speaking of substitutes v, u: and uu.

uu

Interesting, I’ve never seen uu for ü. Of course, third tone vowels are often doubled where diacritical marks are not at hand. Most famous example: “Shaanxi province” (as opposed to “Shanxi province”).
If you are just looking for typographical nuances, the ’ apostrophe, which in pīnyīn marks a glottal stop, is always a candidate for erroneously used glyphs. The breve for the third tone is often a conscious choice when a specific font lacks vowels with caron.
Also note that in zhùyīn annotations, the first tone is not indicated and therefore the neutral (short) tone is denoted by a dot. I sometimes apply the neutral dot even in pinyin, but I don’t know if anyone else does.

Pinyin varieties

> I’ve never seen uu for ü
Neither have I. I found somebody online though stating that NJStar (njstar.com) accepts it.

> Of course, third tone vowels are often doubled where diacritical marks are not at hand.
Do you have other examples? I only know about Shaanxi and as another author noted, it could stem from Gwoyeu Romatzyh which uses vowel doubling for the third tone.

> I sometimes apply the neutral dot even in pinyin, but I don’t know if anyone else does.
I've seen two sources, and noted them down in http://www.stud.uni-karlsruhe.de/~uyhc/api/cjklib.reading.operator.PinyinOperator-class.html. Xiàndài Hànyǔ Cídiǎn does with e.g. ·ma and the pre-Pinyin draft Pinjin seems to use .

I am trying to implement a parser that is forgiving and just added treatment of wrong diacritics last weekend. The neutral tone will hopefully follow later. Then I'll be left with nue, lue which I wrote about some days ago. They give me a bit of a headache as I'm not certain if I want to offer support for left out umlaut all the way.