While reading the Wikipedia article about the 道德经 / 道德經, I noticed how inconsistent it is in its pinyin transcription of that book title. Here are the transliterations found in the article (the link in the previous sentence intentionally points to the current version, since the inconsistency may be edited out of the article at some point after the submission of this question):
- Dàodé Jīng
- Dao De Jing
- Daodejing (e.g. "The title "Daodejing", with its status as a classic, was only first applied from the reign of Emperor Jing of Han (157–141 BCE) onward.")
I am intentionally ignoring the Wade-Giles transcription. That the transcription sometimes includes tone diacritics (for those familiar with pinyin) and sometimes does not (for those who don't know what those dashes mean) is something I can also live with. My concern is the inconsistency in the use of spaces between individual syllables. Previously, I assumed that 道,德 and 经 were three different words, since disyllabic words were rare in Classical Chinese (they were typically loanwords); hence I expected a transcription that uses spaces between each syllable: dào dé jīng (ignoring capitalisation).
However, the Wikipedia article also uses a transliteration without a space between the first two syllables and adds: 'Compare the compound word 道德 (pinyin: dàodé; Wade–Giles: tao⁴-tê²), literally "ethics", "ethical principles", "morals" or "morality".'
Do the official rules of pinyin favour one transliteration (especially "dào dé jīng") over other ones (especially "dàodé jīng")? Do these rules also take into account whether a book title is in Classical Chinese or in modern putonghua? (I add the second question in case 道德 turns out to be a more recent concept than the 道德经 itself.)