Thanks for reaching out Debra! You were told not to use 38 Special +P ammo in your older revolver. That's because "overpressure" ammo, as +P ammo is also known, is loaded to a higher pressure which may damage older firearms that aren't designed for it.
I'm happy to say this is not overpressure ammo. It's standard 38 Special, loaded to the same specifications that your revolver is designed for. The FTX is just Hornady's brand name for this specific type of bullet, which is a jacketed hollow point (JHP) designed for self-defense. It's a high-quality bullet – I personally bought this same type of ammo for the revolver that my father keeps in his bedside drawer.
In short, this is excellent ammo for self-defense with your older 38 Special revolver. Please let me know if you ever have any other questions!