Some updates.
66.6% : Refers to the majority of Singaporeans who voted for PAP.
Usually used sarcastically when the government implements some undesirable policies.
eg. 66.6%, are you happy now that you have to pay extra 2% GST?
Origin : During the 2006 election, PAP won with a 66.6% vote. This number probably got the attention of people due to 666 being the number of the devil.
Ah Tiong : China Man (possibly racist). Tiong = 中 = 中国 = China (see also XLN)
Beethoven : 背多分 (chinese, Back scores more points) = The back view (of a person) is more attractive than the front.
背多分...前面没有分 = Back more points, front zero point
(Nothing to do with the musician in any way)
FR : Field Report
Robert : A person who 1) overpays for something, 2) pays for something not worthwhile, 3) pays for something he's not expected to.
Origin : Comes from the chinese/hokkien saying "砍菜头".
菜头 = Radish = 萝卜
萝卜 sounds like "Robert"
XLN : Xiao Long Nu = China Woman (possibly racist) (see also Ah Tiong)