In the Westlaw database, you may see citations to WLUK. This is Westlaw's own citation system and does not refer to a Law Reporter or published case series.
For example:
X v Oldham MBC [2013] 7 WLUK 159.
[2013] is the year the case was heard.
Next, comes the month of the hearing, so 7 here is July, not a volume number.
WLUK stands for Westlaw United Kingdom.
The 159 is a sequential number assigned to the citation; it is not a page number.
You should only use WLUK if the Westlaw case analysis is the only available version of the case. If there is a neutral citation, or a citation to a published series, these should be used. Remember to check BAILII and Lexis as well as Westlaw itself.