Core - These go in /bin
=======================
at
batch
X cat
chgrp
chmod
chown
cp
crontab
dd
df
dmesg
du
X  echo
X false
file
find
getconf
grep
hostname
X ln
logger
login
ls
mkdir
X mkfifo
mknod
mount
mv
netstat
newgrp
nice
nohup
pathchk
ping
printf
ps
renice
rm
X rmdir
sh
X sleep
stty
su
sync
tar
X tee
time
touch
tput
X true
X tty
umount
X uname
xargs

Important system stuff - These go in /sbin
==========================================
shutdown
fastboot
fasthalt
fdisk
fsck (especially fsck.fxfs)
halt
init
mkfs (especially mkfs.fxfs)
mkswap
reboot
swapon
swapoff
update

Shell built-ins - These may or may not have standalone versions
===============================================================
alias
bg
~ cd
command
env
fc
fg
getopts
hash
jobs
X kill
pwd
read
tabs
test
type
ulimit
umask
unalias
wait

C toolchain - Stuff used for C language development
===================================================
ar
awk
cc/c99
cflow
cxref
lex
yacc

XSI - X/Open Source utilities
=============================
cal
compress
date
fuser
ipcrm
ipcs
X link
nl
uncompress
unlink
zcat

SCCS
====
admin
delta
get
prs
rmdel
sact
sccs
unget
val
what

Dev utils - General development utilities (not C-specific)
==========================================================
asa
ctags
fort77
gencat
m4
make
nm
od
patch
pax
strip

Complex - Utilities that will be difficult, might need lex/yacc or curses, etc.
===============================================================================
bc
ed
ex
expr
join
lp
mailx
more
pr
sed
vi

Multi-user - Utilities for multi-user interactions and the like
===============================================================
id
X logname
mesg
talk
who
write

Obsolete batch job commands
===========================
qalter
qdel
qhold
qmove
qmsg
qrerun
qrls
qselect
qsig
qstat
qsub

Miscellaneous
=============
X basename
X cksum
X cmp
comm
csplit
cut
diff
X dirname
X expand
fold
X head
iconv
locale
localedef
locate
look
man
paste
sort
split
strings
tail
tr
tsort
unexpand
uniq
uucp
uudecode
uuencode
uustat
uux
X wc

Additions - Things not in any standard
======================================
basic (bas?)???
cobol
dump