Reduced proper motion diagram for new ultracool subdwarfs identified in the SDSS DR7 vs. the UKIDSS LAS DR5 search. The small dots represent all sources in the catalogue published by Lépine & Shara (2005, LS05) with their counterpart in the SDSS DR7 database. Our new subdwarfs, extreme subdwarfs, and ultra-subdwarfs are marked as filled squares, circles, and triangles, respectively. Diamonds represent our candidates classified as solar-metallicity M dwarfs. The five sources without optical spectroscopy are marked with a star symbol. Known subdwarfs from the literature are marked as open symbols (Lépine & Scholz 2008, LS08). Left: diagram for the values given by the Virtual Observatory. Right: diagram using the revised proper motions computed with the method detailed in Sect. 3.