Status flags:
---------------
! : not used
- : used without arg
+ : used with argument
* : used with optional argument
# : obsolete
---------------
letters usage:
---------------

a * alteration of operation		--alter	  argument:
							    a[time]
							    binary[-unit[s]]
							    b[lind-to-signatures]
							    c[time]
							    case
							    d[ecremental]
							    do-not-compare-symlink-mtime
							    duc
							    e[rase_ea]
							    f[ixed-date]
							    file-auth[entication]
							    g[lob]
							    h[oles-recheck]
							    header
							    i[gnore-unknown-inode-type]
							    k[eep-compressed]
							    l[axist]
							    list-ea
							    m[ask]
							    n[o-case]
							    r[egex]
						            s[aved]
							    secu
							    SI[-unit[s]]
							    t[ape-marks]
							    test-self-reported-bug
							    y abyte[s]
							    z[eroing-negative-dates]
b - terminal bell                       --bell
c + create archive                      --create
d + difference with filesystem          --diff
e - simulate the operation              --empty (aka dry-run)
f - do not restore directory structure                --flat
g + recurse in this directory           --go-into
h - help usage                          --help
i + path of the input pipe              --input
j + retry delay for networking errors   --network-retry-delay <seconds>
k + do not deleted files dropped between two backups --no-delete / --deleted { ignore | only }
l + list archive contents               --list
m + minimum size below which no compression will occur. --mincompr a default value is used. use -m 0 if you want to compress in any case.
n - do not allow overwriting            --no-overwrite
o + path of the output pipe             --output
p + pause before creating new slice     --pause
q - suppress final statistics report    --quiet
r - do not overwrite more recent file   --recent [=date] (to implement)
s + size of slice                       --slice
t + test archive structure              --test
u + exclude EA from operation (mask)    --exclude-ea
v + verbose output                      --verbose   --verbose={skipped|treated|messages|dir|masks|all}
w * do not warn before overwriting      --no-warn
x + extract archive                     --extract
y + repair archive                      --add-missing-catalogue
z * compression                         --gzip --compress
A + make a differential backup          --ref
B + filename taken as command-line extension --config
C + extract catalogue in separated file --isolate
D - store excluded dir as empty dir     --empty-dir
E + shell command to launch with slices --execute
F + shell command to launch with slices of archive of reference   --execute-ref
G - forbid the use of multi threads when compiled against libthreadar --single-thread
H * if a file for differential backup or diff differs from exactly one hour it is assumed as identical (no change).
I + include mask                        --include
J + key for unscrambling the reference catalogue --key-ref
K + key for un/scrambling               --key
L - license information
M - only consider what is under the current mounting point. --no-mount-points
N - do not read any configuration file ~/.darrc or /etc/darrc
O + ignore user Id and group Id         --ignore-owner
P + prune a directory tree              --prune
Q + quite on stderr at startup		no long option equivalent
R + set the root directory              --root
S + size of the first slice             --first-slice
T + (listing) tree listing format       --tree-format, --list-format=<normal|tree|xml|slicing>
T + (create/merge/isolate) interation count for key derirvation --kdf-param
U + include EA for the operation (mask) --include-ea
V - version information                 --version
W - warranty disclosure information (POSIX RESERVED, sorry)
X + exclude mask                        --exclude
Y + included only filename for compression --include-compression
Z + excluded filename from compression  --exclude-compression
  - don't save files with nodump flag set --nodump
# + encryption block size                 --crypto-block
* + encryption block size for the archive of reference --crypto-block-ref
, - cache directory tagging standard    --cache-directory-tagging
[ + include files listed in given file   --include-from-file
] + exclude files listed in given file   --exclude-from-file
- x (forbidden by getopt)
? x (forbidden by getopt)
: x (forbidden by getopt)
+ + merging operation                    --merge
@ + second reference archive for merging --aux-ref
$ + key for auxilliary refence archive   --aux-key
~ + command to execute between slices    --aux-execute
% + encryption block size for the auxilliary archive of reference --aux-crypto-block
/ + policy to solve overwriting conflict --overwriting-policy
^ + ownership and permission of generated slices --slice-mode
_ + retry on change                      --retry-on-change <count[:max byte]>
{ + include files for delta signature	 --include-delta-sig
} + exclude files for delta signature    --exclude-delta-sig
0 * sequential read of the archive       --sequential-read
1 + sparse-file detection tunning        --sparse-file-min-size <int>
2 + dirty file behavior                  --dirty-behavior {ignore|no-warn}
3 + create a hash algorithm (+algo)      --hash <algo>
4 + filesystem specific attr. family     --fsa-scope <fam1,fam2,fam3,...>
5 + exclude file having a given EA set   --exclude-by-ea [<ea name>]
6 + minimum size for delta signatures    --delta-sig-min-size <int>
7 + define keys used to sign the archive --sign <comma separated list of emails>
8 + delta binary diff                    --delta sig, --delta patch
9 + min_digits                           --min-digits archive[,ref[,aux]];
" + anonymous pipe descriptor to read conf from. --pipe-fd
' + how to detect modified date in diff backup --modified-data-detection= {any-change | crc-comparison}
. + user comment                         --user-comment
; x (forbidden by getopt)
< + backup hook mask                     --backup-hook-include
> + backup hook mask                     --backup-hook-exclude
= + backup hook execute                  --backup-hook-execute
\ + ignored as a symlinks		 --ignored-as-symlinks <absolute path>[:<absolute path]...

