Roy's safety ratio vs. sortino

What’s the difference? I’ve seen in schweser answers both definition of ROY: (Ri - MAR) / std AND (Ri-MAR)/Downside dev) But in the latter case, it’s the same than sortino’s… can someone help? thx

in roy, you use st dev. when they used downside dev for roy, it was a mistake, it is in schweser errata

ok thanks