TL;DR

It’s fine to use v5.X.Y with the v when asking for a minimum perl version and its related features.

More and more in the past days I read about setting a use v5.X or use v5.X.Y line early in Perl programs, just to get all benefits of that specific perl version out of the box.

This started to itch a bit after some time because in all those places they were suggesting to use the v-string form, i.e. prefixing the version with the letter v. The itch was that I was used to using:

use 5.024; # no "v", and a "0" before "24"

instead, for reasons that I understood at the time I chose this form, but that I obviously obliviated on the spot.

So, what’s better? It turns out that putting the v is, in 2021, mostly fine. Well, totally fine in my (new) opinion.

From the use documentation:

Specifying VERSION as a numeric argument of the form 5.024001 should generally be avoided as older less readable syntax compared to v5.24.1. Before perl 5.8.0 released in 2002 the more verbose numeric form was the only supported syntax, which is why you might see it in

use v5.24.1;    # compile time version check
use 5.24.1;     # ditto
use 5.024_001;  # ditto; older syntax compatible with perl 5.6

So there you have it, I was using the 5.024 form just to make sure that some perl from middle ages would properly parse it and, in any case, complain that it could not execute it.

Additional elaborations regarding version numbers (although on the setting side, not on the useing side) can be found here: Version numbers should be boring.

Bottom line: it’s fine to use v5.X.Y; with the v to settle for a minimum perl version in 2021.