rst2s5: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/rst2s5 - from package: python-docutils

You may install the required package with command yum install {package}

Error in other languages:
rst2s5: bevel nie gevind nie
rst2s5: comandă negăsită
rst2s5: comando não encontrado
rst2s5: commande introuvable
rst2s5: command not found
rst2s5: käsku ei ole
rst2s5: không tìm thấy lệnh
rst2s5: komanda nerasta
rst2s5: Kommando nicht gefunden.
rst2s5: kommandot finns inte
rst2s5: komut yok
rst2s5: nie znaleziono polecenia
rst2s5: níor aimsíodh an t-ordú
rst2s5: no se encontró la orden
rst2s5: no s'ha trobat l'ordre
rst2s5: opdracht niet gevonden
rst2s5: parancs nem található
rst2s5: perintah tidak ditemukan
rst2s5: príkaz nenájdený
rst2s5: příkaz nenalezen
rst2s5: команда не найдена
rst2s5: командата не е открита
rst2s5: 命令找不到
rst2s5: コマンドが見つかりません