I have a set of files on my computer whose names and extensions I changed manually. The renamed extensions work for my purposes. Except: two particular files (out of hundreds) are found if I perform a search in the finder toolbar or in Searchlight for files whose type is the old extension. Most files with the same (old) extension which I changed to the alternative extension do not show up under this search, which is set to search on my entire HD with no restriction other than file type. But...
"ghost" file names and extensions found in a search despite having been renamed
"ghost" file names and extensions found in a search despite having been renamed