-Complete file name FILE in directory DIRECTORY.
-Returns the longest string common to all filenames in DIRECTORY
-that start with FILE.
-If there is only one and FILE matches it exactly, returns t.
-Returns nil if DIRECTORY contains no name starting with FILE.
-
-Filenames which end with any member of `completion-ignored-extensions'
-are not considered as possible completions for FILE unless there is no
-other possible completion. `completion-ignored-extensions' is not applied
-to the names of directories.
+Complete file name PARTIAL-FILENAME in directory DIRECTORY.
+Return the longest prefix common to all file names in DIRECTORY
+that start with PARTIAL-FILENAME.
+If there is only one and PARTIAL-FILENAME matches it exactly, return t.
+Return nil if DIRECTORY contains no name starting with PARTIAL-FILENAME.
+
+File names which end with any member of `completion-ignored-extensions'
+are not considered as possible completions for PARTIAL-FILENAME unless
+there is no other possible completion. `completion-ignored-extensions'
+is not applied to the names of directories.