Absolutely. To reconfirm what was said above:

My corporate rate (massive global firm) gives a fixed X% off BAR on any Marriott property worldwide for a base room. Certain properties extend this to cover more than just a base room (e.g. a discount on the club floor), but it isn't mandated. They typically say "X miles to the office and free wifi".

Then, in cities where we clearly have a lot of spend, a local property will give a much steeper discount, that is available globally anyway -> as we are mandated to use a global booking system, so if the property didn't load the rate to the standard corporate code then they would not be able to get people to use it (plus it would reduce its usefulness). This is often fairly generically described as "[Corporate] discount code" with few extra details, a "lazy" local property set-up

Finally, I have seen some properties that go even further than the pure code discount, and start to get (Hilton-like) city specific bonus rate discounts (often a few bonus points, particularly for stays over a certain number of nights). These may hint at treats within the description, but more likely in the rate rules it will talk about bonus points.... sometimes they are expired already months previously, but left in the system

So what does this mean:
1. Read the rate rules, they should be clear if there are any extra perks
2. No different rate rules, just presume it is a cash discount and there is no need to worry, just book the cheapest as the chances are none will include breakfast, if there are some freebies (does anyone pay for wifi anymore?) then it would be consistent unless specified in the rate rules.