This code system http://hl7.org/fhir/map-transform defines the following codes:

CodeDisplayDefinition
createcreatecreate(type : string) - type is passed through to the application on the standard API, and must be known by it
copycopycopy(source)
truncatetruncatetruncate(source, length) - source must be stringy type
escapeescapeescape(source, fmt1, fmt2) - change source from one kind of escaping to another (plain, java, xml, json). note that this is for when the string itself is escaped
castcastcast(source, type?) - case source from one type to another. target type can be left as implicit if there is one and only one target type known
appendappendappend(source...) - source is element or string
translatetranslatetranslate(source, uri_of_map) - use the translate operation
referencereferencereference(source : object) - return a string that references the provided tree properly
dateOpdateOpPerform a date operation. *Parameters to be documented*
uuiduuidGenerate a random UUID (in lowercase). No Parameters
pointerpointerReturn the appropriate string to put in a reference that refers to the resource provided as a parameter
evaluateevaluateExecute the supplied fluentpath expression and use the value returned by that
ccccCreate a CodeableConcept. Parameters = (text) or (system. Code[, display])
ccCreate a Coding. Parameters = (system. Code[, display])
qtyqtyCreate a quantity. Parameters = (text) or (value, unit, [system, code]) where text is the natural representation e.g. [comparator]value[space]unit
ididCreate an identifier. Parameters = (system, value[, type]) where type is a code from the identifier type value set
cpcpCreate a contact details. Parameters = (value) or (system, value). If no system is provided, the system should be inferred from the content of the value