There is a standard for transferring medical information between and within medical facilities called HL7, or Health Level 7. It's a fairly simple text protocol with fields designated for particular types of data separated by pipes ( | ). Those fields are sometimes then further divided. This standard is meant to ease the flow of data between disparate systems. Within a hospital you may have a radiology information system (RIS), an EHR or EMR, practice management software, scheduling software, PACS archive, lab software, interface engines, emergency department systems, and a whole host more. These are systems are made by niche companies you've never heard of, and large corporations that everyone's heard of. All of these systems need to talk to each other to some degree.
Here's the dirty little secret that makes my job more difficult...
NO ONE FOLLOWS THE STANDARD!
Seriously. Here's how a call between me and a vendor might go (simplified):
Me: Where is the scheduled datetime?
Vendor: It's in field C.
Me: But that's where the observation datetime should be. So where's the obs time?
Vendor: Oh that's in field A.
Me: Field A is for completed datetime. So where that then?
Vendor: We put that in field B.
M: Are you messing with me?
Me: Grrr. Field B is where the scheduled datetime should be!!! Why is it built like this?
Vendor: Mmmm...not sure. I'll have to check with one of the engineers and get back to you.
Me: You may want to give them the HL7 specification while you're at it. It's published. Online. Freely accessible. You want the link?
It'd be like every web browser and web server all agreeing upon a standard markup language, HTML for instance; then each rolling their own version anyway. So Chrome looks for a HEAD tag, but IE calls it the TOP tag, Apache calls it the BEGIN tag, and IIS uses a FRONT tag. You may be thinking, well since IE and IIS are both from Microsoft they wouldn't do that. And my answer would be, you obviously haven't delved into the world of SharePoint.