English law reports are very commonly cited. The traditional citations are from the printed reports, the All England Law Reports and the Law Reports. Times Law Reports can also be quoted in court (theyre written and signed by a barrister). And all these reports refer to the paper publication.
Now so many judgments are published on the Internet, a form of citation called neutral citation has been introduced. The Bodleian Library explains it.
and there is a practice direction too:
(these two texts are very similar).
A “neutral citation standard” is a means of citing court judgments without reference to specific publishers, databases or report series.
Here are the abbreviations used for various courts:
bq. Chancery Division EWHC number (Ch)
Patents Court: EWHC number (Pat)
Queen’s Bench Division EWHC number (QB)
Administrative Court EWHC number (Admin)
Commercial Court EWHC number (Comm)
Admiralty Court EWHC number (Admlty)
Technology & Construction Court EWHC number (TCC)
Family Division EWHC number (Fam)
For example,  EWHC 123 (Fam); or  EWHC 124 (QB); or  EWHC 125 (Ch).
(from practice direction)
Neutral citation has been introduced in other common-law countries too.
US site defines vendor-neutral and medium-neutral citation systems.
German case reports are not so strictly reported, since Germany does not have a case-law system. They are often cited by the periodical they appeared in. But each judgment has its file number, and that is the number usually given when a judgment appears on the Web.