During design, yes. Project folder with Mechanical/Electrical Design subfolders. Upon release, everything is renamed and moved (automatically) to folders containing blocks of 1000 numbers. So, folder 400xxx contains 400000 through 400999.
In the project folder, you can name things whatever you like. It’s a sandbox. Some parts never make it out of there, so there are no naming rules. The released parts have dumb, sequential numbers for file names. If users want to find something, they can search by whatever (part number, description, etc.) thanks to PDM.
Started out doing that back in 1998. Quickly determined it was a bad idea since SW likes to save things in the last place you saved something, so lots of files wound up in the wrong place.
Extensively during design. If I’m basing a design on an existing one, I save a copy of the top level assembly. As I touch parts to make modifications, I make them virtual, and give them a name that is descriptive but points back to the original in case I don’t actually end up changing the part (e.g. BRACKET - WAS 435123). Any upstream assemblies are also made virtual as needed. When the design is done, anything in the tree that is virtual (and doesn’t have a part number for its name) is saved to an external file before release.
I also use virtual parts for things such as tubing that need to be shown but don’t necessarily have to be on the BOM.
Another use case is models of purchased parts that are assemblies. Download an air cylinder as an assembly model, make all the parts in it virtual and change the names to something more descriptive (body, piston, rod, sensor, etc). Now this one thing we buy is in one file with one part number but can still be put in an assembly and be made flexible and such.
One key thing to remember about virtual parts is that SW makes a real file in your Windows TEMP folder, not the SW Backup folder. If you aren’t careful, you can run out of space, SW will not behave well and the reason won’t be obvious.