What are the POSIX “mandatory utilities”?

Question

The POSIX docs here and here refer to "mandatory utilities", but I can't find any listing of such utilities. Is there one somewhere in the POSIX docs?

Granted, the links given above point to older version of the docs. Maybe the nomenclature has changed since then (E.g., maybe what used to be called "mandatory utilities" are now called "required utilities", or "obligatory utilities", or "core utilities", etc.) or the mandatory/optional distinction has been dropped altogether? Clarifications welcome.

Answer 1

From one of the sections that you cite:

Optional utilities that are present only on systems supporting the associated option; see Codes for information on the options in this volume of IEEE Std 1003.1-2001

The mandatory utilities are the ones that are not marked as optional.

For example basename has no annotation to indicate that it's optional, so it's mandatory. alias is annotated as UP, so it's only mandatory if an implementation claims to include the User Portability Utilities option. command is mandatory, but the -v and -V options are not unless the implementation claims to include the User Portability Utilities option.

Answer 2

https://pubs.opengroup.org/onlinepubs/9699919799/idx/xcu.html

It depends on how "compliant" a system is, but you can check the list:

Utilities

admin
alias
ar
asa
at
awk
basename
batch
bc
bg
c99
cal
cat
cd
cflow
chgrp
chmod
chown
cksum
cmp
comm
command
compress
cp
crontab
csplit
ctags
cut
cxref
date
dd
delta
df
diff
dirname
du
echo
ed
env
ex
expand
expr
false
fc
fg
file
find
fold
fort77
fuser
gencat
get
getconf
getopts
grep
hash
head
iconv
id
ipcrm
ipcs
jobs
join
kill
lex
link
ln
locale
localedef
logger
logname
lp
ls
m4
mailx
make
man
mesg
mkdir
mkfifo
more
mv
newgrp
nice
nl
nm
nohup
od
paste
patch
pathchk
pax
pr
printf
prs
ps
pwd
qalter
qdel
qhold
qmove
qmsg
qrerun
qrls
qselect
qsig
qstat
qsub
read
renice
rm
rmdel
rmdir
sact
sccs
sed
sh
sleep
sort
split
strings
strip
stty
tabs
tail
talk
tee
test
time
touch
tput
tr
true
tsort
tty
type
ulimit
umask
unalias
uname
uncompress
unexpand
unget
uniq
unlink
uucp
uudecode
uuencode
uustat
uux
val
vi
wait
wc
what
who
write
xargs
yacc
zcat

Answer 3

All utilities are mandatory except when they are marked special.

Look e.g. at the documentation for the get command that is maked with the "Development" tag.

Check e.g. Chapter 1.7.1 and look for the tag "optional".