I once registered five of them ML-L.COM NR-R.COM LC-C.COM LV-L.COM and SF-T.COM . Waited for two years and dropped all of them. Don't know if their market changed or not. I advice investigate well then invest.
Note: ml-l.com taken by a company for a link to their long domain.
lv-l.com taken by a chinese company and developed.
lc-c.com and sf-t.com taken.
nr-r still available.