What exactly does "Hospital Grade" mean?

Here is a link to the official explanation. It's a PDF, you need a reader to view.

http://www.ul.com/regulators/ReceptacleGrades_Kurten_JF2005.pdf

It's nice for those of us that have heavy weight power cables, because they're held more securely.

Hospital grade sockets perform this function well because they're designed for health care environment where uninterrupted power is important.

There are also several commercial grade sockets that have excellent grip. Almost any brand "premium socket" is superior to the .49 cent ones used in construction of new homes and apartments.

Dozens of companies provide premium aftermarket outlets, and like power cables, some audiophiles use them and some do not.

There are readily-available 3-pin plugs (and sockets) that twist to lock.

I use exactly that for my 240 volt connections and have for several years.

However, some aftermarket power cords void warranty if modifications are made, and if wired improperly could cause damage to your equipment or your home.

The 120 Volt Hospital grade sockets I provided a link to as well as other aftermarket high quality outlets conform to roughly the same size specifications (fit in existing box) and wire identically to common household outlets.

In other words, a heavier, higher grade product in the wall that requires no modifications to existing male plugs.