rst2html: 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/rst2html - from package: python-docutils

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

Error in other languages:
rst2html: bevel nie gevind nie
rst2html: comandă negăsită
rst2html: comando não encontrado
rst2html: commande introuvable
rst2html: command not found
rst2html: käsku ei ole
rst2html: không tìm thấy lệnh
rst2html: komanda nerasta
rst2html: Kommando nicht gefunden.
rst2html: kommandot finns inte
rst2html: komut yok
rst2html: nie znaleziono polecenia
rst2html: níor aimsíodh an t-ordú
rst2html: no se encontró la orden
rst2html: no s'ha trobat l'ordre
rst2html: opdracht niet gevonden
rst2html: parancs nem található
rst2html: perintah tidak ditemukan
rst2html: príkaz nenájdený
rst2html: příkaz nenalezen
rst2html: команда не найдена
rst2html: командата не е открита
rst2html: 命令找不到
rst2html: コマンドが見つかりません