Generally speaking it doesn't include management (except for immediate dev management). It also doesn't include support or operations (in a software company that would include secretaries, security, cleaning staff, etc). It usually doesn't include capital expenses either, so depending on how you do the accounting, things like running the building is not included. From that perspective, the numbers can be a bit deceiving.
Depending on the area, the costs can swing wildly. I worked at Corel back when shrink wrapped software was a thing. Sales channels cost huge amounts of money. Even after that period getting your software into OEM builds cost a fortune. That's stuck in "costs of sales", usually. I've worked at companies where costs of sales was well over 50% of revenue. As you can imagine, there is considerable latitude for corruption ;-).
If you are running a service, "operations" often pays for compute infrastructure, but it depends entirely on the company. You might even have dev ops in operations so that can be misleading because you don't have a product without the service.
My experience has been that management, operations and sales takes 60-70% of revenue. The absolutely necessary expenses in operations usually amount to less than 10%. Capital expenses can be very large if they are investing in real estate or something similar, so that's a complete wild card. Sales and marketing are kind of linked because usually you have to spend more on one if you spend less on the other. How much you can get away with if you change the business model is kind of up in the air and I'm really speculating when I suggest that a free software model will be cheaper -- I believe it, but obviously have zero data.
It's worth downloading quarterly/year end reports from various high tech companies and reading them. It's pretty incredible how much information you can get from them. They won't break down everything exactly the way you want, but you can usually figure it out -- and often see pretty plainly where they are playing games.
Complete diversion: One of Corel's favourite tricks in the past (though not now, I think -- everything changed after they were sold) was to overfill the sales channel in first quarter. Basically they would "sell" the software to dealers, but would provide "refunds" for software that wasn't sold by the end of 4th quarter. So 1st quarter was always massively positive, while they were always massively (and somehow unexpectedly) in the red by 4th quarter. Executive stock options were granted 4th quarter and there was a trading window in second quarter. So the stock would plunge dramatically (one or two binary orders of magnitude) just before the stock options were granted and then rocket back up in time to sell them. They did that year after year after year (I was there for 5 years and it happened every time). The reason for the swings was literally written in the quarterly reports. In first quarter they would say "We sold $X, but this is subject to 4th quarter refunds". Then in fourth quarter they would say, "We experienced a one time loss from refunds in the sales channel". I swear nobody reads those quarterly reports... :-P