This will probably just confuse the situation... (americans and English... similar peoples separated by a common language, no?) but here in the U.S. the finish on a lot of older ceilings was (and is) called 'popcorn finish'. It's a sprayed on finish that produced a not-unattractive mottled effect, especially when small, sparkly stuff is mixed in the application. However, as with all thing sold to consumers, it has gone out of style. If you watch programs like "House Hunters" negative comments are always given concerning the "popcorn ceilings". Looks like this since my word picture is a little weak:
http://www.google.com...1t:429,r:15,s:0,i:106 ... (apologies for the URL).
Good thing is it's easily removed. A spray bottle ot typical garden sprayer (pump-up kind) filled with warm water, dish soap and liquid fabric softener applied liberally but not dripping, allowed to sit for 10 minutes or so and then simply scraped off with a 5 or 6 inch wide "putty knife). Makes a mess, but spreading the cheap plastic paint overspray protector material takes up most of the mess.
This type of finish was used extensively in the '50's thorugh the '80's, but now, smooth, painted ceilings are all the rage. After removal, a skim cat is reapplied to the ceiling to fill in the dips and uneven areas, finished with a coat of sealant and then painted as you wish. A few of the older ones did have some asbestos in the sprayed on particles, but the wet method of taking it down alleviates any concern...