This code system http://hl7.org/fhir/endpoint-environment defines the following codes:

CodeDisplayDefinition
prod ProductionProduction environment and is expected to contain real data and should be protected appropriately
staging StagingStaging environment typically used while preparing for a release to production
dev DevelopmentDevelopment environment used while building systems
test TestTest environment, it is not intended for production usage.
train TrainingTraining environment, it is not intended for production usage and typically contains data specifically prepared for training usage.
<status value="active"/><experimental value="false"/><date value="2021-01-05T10:01:24+11:00"/><publisher value="HL7 (FHIR Project)"/><description value="The environment type of the endpoint."/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/endpoint-environment"/><content value="complete"/><concept><code value="prod"/><display value="Production"/><definition value="Production environment and is expected to contain real data and should be protected appropriately"/></concept><concept><code value="staging"/><display value="Staging"/><definition value="Staging environment typically used while preparing for a release to production"/></concept><concept><code value="dev"/><display value="Development"/><definition value="Development environment used while building systems"/></concept><concept><code value="test"/><display value="Test"/><definition value="Test environment, it is not intended for production usage."/></concept><concept><code value="train"/><display value="Training"/><definition value="Training environment, it is not intended for production usage and typically contains data specifically prepared for training usage."/></concept></CodeSystem>