notab: 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 Debian possible default full paths are:

/usr/bin/notab - from package: emboss

You may install the required package with command apt-get install {package}

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