diff --git a/share/completions/ls.fish b/share/completions/ls.fish
index 418a67a90..4fe28951e 100644
--- a/share/completions/ls.fish
+++ b/share/completions/ls.fish
@@ -3,32 +3,32 @@
 #
 
 # Shared ls switches
-complete -c ls -s C -d "List by columns"
+complete -c ls -s C -d "Force multi-column output"
 complete -c ls -s S -d "Sort by size"
-complete -c ls -s c -d "Show and sort by ctime"
-complete -c ls -s f -d "Don't sort"
-complete -c ls -s g -d "Long format without owner"
-complete -c ls -s k -d "Set blocksize to 1kB"
-complete -c ls -s l -d "Long format"
-complete -c ls -s m -d "Comma separated format"
-complete -c ls -s t -d "Sort by modification time"
-complete -c ls -s u -d "Show access time"
-complete -c ls -s x -d "List entries by lines"
-complete -c ls -s 1 -d "List one file per line"
+complete -c ls -s m -d "Comma-separated format, fills across screen"
+complete -c ls -s x -d "Multi-column output, horizontally listed"
+complete -c ls -s 1 -d "List one entry per line"
+
+complete -c ls -s f -d "Unsorted output, enables -a"
+complete -c ls -s t -d "Sort by modification time, most recent first"
+
+complete -c ls -s c -d "Sort (-t) by modified time and show time (-l)"
+complete -c ls -s u -d "Sort (-t) by access time and show time (-l)"
 
 # Test if we are using GNU ls
 if command ls --version >/dev/null 2>/dev/null
+    complete -c ls -s k -d "Set blocksize to 1kB" # BSD ls -k enables blocksize *output*
     complete -c ls -s a -l all -d "Show hidden"
     complete -c ls -s A -l almost-all -d "Show hidden except . and .."
-    complete -c ls -s F -l classify -d "Append filetype indicator"
+    complete -c ls -s F -l classify -d "Append filetype indicator (*/=>@|)"
     complete -c ls -s H -l dereference-command-line -d "Follow symlinks"
     complete -c ls -s L -l dereference -d "Follow symlinks"
     complete -c ls -s R -l recursive -d "List subdirectory recursively"
-    complete -c ls -s b -l escape -d "Octal escapes for non graphic characters"
+    complete -c ls -s b -l escape -d "Octal escapes for non-graphic characters"
     complete -c ls -s d -l directory -d "List directories, not their content"
     complete -c ls -s h -l human-readable -d "Human readable sizes"
     complete -c ls -s i -l inode -d "Print inode number of files"
-    complete -c ls -s n -l numeric-uid-gid -d "Long format, numeric IDs"
+    complete -c ls -s n -l numeric-uid-gid -d "Long format, numeric UIDs and GIDs"
     complete -c ls -s p -l file-type -d "Append filetype indicator"
     complete -c ls -s q -l hide-control-chars -d "Replace non-graphic characters with '?'"
     complete -c ls -s r -l reverse -d "Reverse sort order"
@@ -38,7 +38,7 @@ if command ls --version >/dev/null 2>/dev/null
     complete -c ls -l group-directories-first -d "Group directories before files" -r
     complete -c ls -l hide -d "Do not list implied entries matching specified shell pattern" -r
     complete -c ls -l lcontext -d "Display security context"
-    complete -c ls -l context -s Z -d "Display  security  context  so  it fits on most displays"
+    complete -c ls -l context -s Z -d "Display security  context  so  it fits on most displays"
     complete -c ls -l scontext -d "Display only security context and file name"
     complete -c ls -l author -d "Print author"
     complete -c ls -l block-size -x -d "Set block size"
@@ -54,7 +54,7 @@ if command ls --version >/dev/null 2>/dev/null
     complete -c ls -s I -l ignore -r -d "Skip entries matching pattern"
     complete -c ls -s N -l literal -d "Print raw entry names"
     complete -c ls -s o -d "Long format without groups"
-    complete -c ls -l show-control-chars -d "Non graphic as-is"
+    complete -c ls -l show-control-chars -d "Non-graphic characters printed as-is"
     complete -c ls -s Q -l quote-name -d "Enclose entry in quotes"
     complete -c ls -l quoting-style -x -a "literal locale shell shell-always c escape" -d "Select quoting style"
     complete -c ls -l sort -x -d "Sort criteria" -a "
@@ -84,30 +84,91 @@ if command ls --version >/dev/null 2>/dev/null
     complete -c ls -l help -d "Display help and exit"
     complete -c ls -l version -d "Display version and exit"
 else
-    # If not a GNU system, assume we have standard BSD ls features instead
-    complete -c ls -s B -d "Octal escapes for non graphic characters"
-    complete -c ls -s G -d "Use colors"
-    complete -c ls -s I -d "Prevent -A from being automatically set for root"
-    complete -c ls -s P -d "Don't follow symlinks"
-    complete -c ls -s T -d "Show modification time"
-    complete -c ls -s W -d "Show whiteouts when scanning directories"
-    complete -c ls -s Z -d "Display each file's MAC label"
-    complete -c ls -s o -d "Include the file flags in a long (-l) output"
-    complete -c ls -s w -d "Print raw entry names"
+    set -l uname (uname -s)
+    ####              ls on the BSDs                 ####
+    # From latest checked-in man pages as of Nov 2018.
+    # Reformatted with Open Group's ordering and spacing,
+    # then sorted by prevelance, consolidating option
+    # matches.
 
-    complete -c ls -s a -d "Show hidden"
-    complete -c ls -s A -d "Show hidden except . and .."
-    complete -c ls -s F -d "Append filetype indicator"
-    complete -c ls -s H -d "Follow symlinks"
-    complete -c ls -s L -d "Follow symlinks"
-    complete -c ls -s R -d "List subdirectory recursively"
-    complete -c ls -s b -d "Octal escapes for non graphic characters"
-    complete -c ls -s d -d "List directories, not their content"
-    complete -c ls -s h -d "Human readable sizes"
-    complete -c ls -s i -d "Print inode number of files"
-    complete -c ls -s n -d "Long format, numeric IDs"
-    complete -c ls -s p -d "Append filetype indicator"
+    #              [         IEEE 1003.1-2017 options         ]  [ extension options ]
+    # freebsd: ls -[ikqrs][glno][Aa][Cmx1][Fp][LH][Rd][Sft][cu]  [ThBbWwPUG ZyI,     ] [-D format] [--color=when] [file ...]
+    # netbsd:  ls -[ikqrs][glno][Aa][Cmx1][Fp][L ][Rd][Sft][cu]  [ThBbWwP       XMO  ] [file ...]
+    # macOS:   ls -[ikqrs][glno][Aa][Cmx1][Fp][LH][Rd][Sft][cu]  [ThBbWwPUG       Oe@] [file ...]
+    # openbsd: ls -[ikqrs][glno][Aa][Cmx1][Fp][LH][Rd][Sft][cu]  [Th                 ] [file ...]
+
+    # netbsd ls -O: only leaf files, no dirs | macos ls -O: include file flags in -l output
+    # so: don't complete -H for netbsd, and return early after the ls -P completion.
+    #     But not before adding their -B, -X, -M, -O options. Same kind of thing for the other OSes.
+
+    ## IEEE 1003.1-2017 standard options:
+
+    complete -c ls -s i -d "Show inode numbers for files"
+    complete -c ls -s k -d "for -s: Display sizes in kB, not blocks" # GNU sets block size with -k
     complete -c ls -s q -d "Replace non-graphic characters with '?'"
     complete -c ls -s r -d "Reverse sort order"
-    complete -c ls -s s -d "Print size of files"
+    complete -c ls -s s -d "Show file sizes"
+
+    complete -c ls -s g -d "Show group instead of owner in long format"
+    complete -c ls -s l -d "Long listing format"
+    complete -c ls -s n -d "Long format, numerical UIDs and GIDs"
+    complete -c ls -s o -d "Long format, omit group names" # POSIX. FreeBSD enables file flags!
+
+    complete -c ls -s A -d "Show hidden except . and .."
+    complete -c ls -s a -d "Show hidden entries"
+
+    # -C in common, -m in common, -x in common, -1 in common
+
+    complete -c ls -s F -d "Append indicators. dir/ exec* link@ socket= fifo| whiteout%"
+    complete -c ls -s p -d "Append directory indicators"
+
+    complete -c ls -s L -d "Follow all symlinks Cancels -P option"
+    test "$uname" != NetBSD
+        and complete -c ls -s H -d "Follow symlink given on commandline" # not present on netbsd
+
+    complete -c ls -s R -d "Recursively list subdirectories"
+    complete -c ls -s d -d "List directories, not their content"
+
+    # -S in common, -f in common, -t in common
+
+    # -c in common, -u in common
+
+    ## These options are not standardized, but seem supported everywhere:
+    complete -c ls -s T -d "for -l: Show complete date and time"
+    complete -c ls -s h -d "Human-readable sizes"
+
+    if [ "$uname" = OpenBSD ] # no arguments supported after -h on OpenBSD. See table above
+        exit 0
+    end
+
+    complete -c ls -s B -d "Octal escapes for non-graphic characters"
+    complete -c ls -s b -d "C escapes for non-graphic characters"
+    complete -c ls -s W -d "Display whiteouts when scanning directories"
+    complete -c ls -s w -d "Force raw printing of non-printable characters"
+    complete -c ls -s P -d "Don't follow symlinks"
+    if [ "$uname" = NetBSD ]
+        complete -c ls -s X -d "Don't cross mount points when recursing"
+        complete -c ls -s M -d "for -l, -s: Format size/count with commas"
+        complete -c ls -s O -d "Show only leaf files (not dirs), eliding other output"
+        exit 0
+    end
+    complete -c ls -s U -d "Sort (-t) by creation time and show time (-l)"
+    complete -c ls -s G -d "Enable colorized output" # macos, freebsd.
+
+    switch "$uname"
+        case Darwin:
+            complete -c ls -s O -d "for -l: Show file flags"
+            complete -c ls -s e -d "for -l: Print ACL associated with file, if present"
+            complete -c ls -s @ -d "for -l: Display extended attribute keys and sizes"
+            exit 0
+        case FreeBSD:
+            complete -c ls -s Z -d "Display each file's MAC label"
+            complete -c ls -s y -d "for -t: Sort A-Z output in same order as time output"
+            complete -c ls -s I -d "Prevent -A from being automatically set for root"
+            complete -c ls -s , -d "for -l: Format size/count number groups with ,/locale"
+
+            complete -r -c ls -s D -d "for -l: Format date with strptime string"
+            complete -c ls -l color -f -a "auto always never" -d "Enable color output"
+            exit 0
+    end
 end