standard width of 3 characters maybe? makes visual scanning of a list of names easy to do to spot name/purpose, environtment, geo, etc. you don't have to keep moving your eyes left or right with each row.
If you're regularly typing the names, it's nicer to type something short like
ssh prd01
rather than
ssh production-01
On the other hand if you're managing clusters of servers using something like ansible, you may not spend as much time typing in individual server names. I think it may depend on how your workflow is set up.
Typing test and prod is likely faster than typing tst and prd because you're not accustomed to leaving out vowels. Short doesn't have to mean no vowels. Short real words are better than abbreviations.
Because 3 letter grouping is visually easier if you use that for every environment. dev, tst, prd, stg, ppd, bkp. Combines well with geographic locations by using airport codes also.
Actual words are better for all environments; abbreviations are ridiculous. They don't speed anything up, they slow down comprehension and they make jargon where none is warranted.
The words you speak should be the words you use, not abbreviations of them. You don't say prd, you say prod, you don't say tst, you say test, so prod and test are what you should use. One ubiquitous language everyone can share without the burden of useless jargon. Dropping out vowels isn't saving you anything.
Except the consistency thing I was talking about. In one of previous job at a fortune 100 company had to have a consistent naming scheme for everything in the DC for whatever reason that predated me. 3 letter production environment, followed by a 4 digit number which described all kinds of things about what apps / environments ran on the host.
Also having fixed with fields for hosts is very valuable when you are writing scripts to parse data on hostnames, especially when you are scaling up to tens / hundreds of thousands of hosts you begin to appreciate consistency.
I think the question is about what is good, not what do you do when you're stuck working with a bad standards, and those are bad standards. Relying on fixed length host names is as bad as relying on fixed length data or fixed length file names, i.e. it's absurdly bad practice. These are things developers learned sucked long ago. Fixed width is not valuable, it's brittle.
I wouldn't use fixed values myself, but when I've worked at places with 100k+ hosts using naming schemes with consistent abbreviations of the same lengths, with other fields describing consistent data is much better than fun names when you need to fix things quickly.
Different story for small networks, have fun all you want. With hundreds of thousands of hosts scattered all over the world, this isn't used.
If you got it, you wouldn't be putting up a straw man of long server names like "production-mail-server-and-occasional-nas-file-server" so no, you really don't get it because you aren't listening.
You can have short server names that are easy to type AND still use actual words. Typing prd instead of prod is not saving you anything worth saving nor making server names easier to type or remember no matter how many there are.
The real world companies I've worked for in the past have good reason to use abbreviated host names, sorry this is so offensive, but that's...real life?
That's a good point about dropping vowels. Typing 'prod' feels more natural than typing 'prd'. But even 'ssh' and 'prod' are abbreviations. It's not the case that you never want to abbreviate, even for host names.
Prod is not an abbreviation, it's a nickname; big difference. SSH is, but Linux is full of badly named commands that you just have to suck up and learn and that's been its Achilles heel for a great many years, it's the ultimate jargon.
