This case-sensitive code system http://hl7.org/fhir/uv/vhdir/CodeSystem/ehrcharacteristics defines the following codes:
Code
Display
Definition
2011
ONC 2011 Certification
The ONC 2011 Certification Edition
2014
ONC 2014 Certification
The ONC 2014 Certification Edition
2015
ONC 2015 Certification
The ONC 2015 Certification Edition
portal
patient portal
A patient portal is a secure online website that gives patients convenient, 24-hour access to personal health information from anywhere with an Internet connection
messaging
secure messaging
EHR functionality that enables a user to send messages to, and receive messages from, a patient in a secure manner
VDT
view/download/transmit (VDT)
EHR functionality that enables patients (and their authorized representatives) to use internet-based technology to view, download, and transmit their health information to a 3rd party.