# text.div
This case-sensitive code system http://hl7.org/fhir/type-characteristics-code defines the following codes in a Is-A hierarchy:

Lvl | Code | Display | Definition
1 | has-target | Has Target | The type is reference to external content else where that can have a type. This is associated with the use of ElementDefinition.type.targetProfile
1 | has-range | Has Range | The type has a value domain that is a range, and can be associated with allowable min/max values on it's ElementDefinitions
2 | is-continuous | Is Continuous | The type is a continuous distribution. These types have issues associated with precision and equality, and can have a specified number of max decimal places (via an extension)
1 | has-length | Has Length | The type has variable length and be constrained by it's length. In principle, any type can be constrained by the number of characters to represent it, but this is not meaningful for numbers or attachments
1 | has-size | Has Size | The type can be constrained by the number of bytes it takes to represent the content. This is usually applied to content that is compressed or interpreted, and there's no fixed relationship between the number of bytes of content, and the number of characters it represents
1 | can-bind | Can Bind | The type can be bound to a terminology. Note that a classic binding has system|version|code|display, but not all bindable types carry all four of these, and how they are bound varies, so an additional extension is required to enable tools to work with this content
1 | has-units | Has Units | The content has units of measure (UCUM, by implication) and it may be useful to constrain the units by some valueset
1 | do-translations | Do Translations | The content is uncontrolled human readable text that may make sense to translate
1 | can-be-target | Can Be Target | The content has an identify and can be persisted with an appropriate life cycle such that it can be the target of a reference from a resource or another logical model

# concept[].definition
The type is reference to external content else where that can have a type. This is associated with the use of ElementDefinition.type.targetProfile

# concept[].definition
The type has a value domain that is a range, and can be associated with allowable min/max values on it's ElementDefinitions

# concept[].concept[].definition
The type is a continuous distribution. These types have issues associated with precision and equality, and can have a specified number of max decimal places (via an extension)

# concept[].definition
The type has variable length and be constrained by it's length. In principle, any type can be constrained by the number of characters to represent it, but this is not meaningful for numbers or attachments

# concept[].definition
The type can be constrained by the number of bytes it takes to represent the content. This is usually applied to content that is compressed or interpreted, and there's no fixed relationship between the number of bytes of content, and the number of characters it represents

# concept[].definition
The type can be bound to a terminology. Note that a classic binding has system|version|code|display, but not all bindable types carry all four of these, and how they are bound varies, so an additional extension is required to enable tools to work with this content

# concept[].definition
The content has units of measure (UCUM, by implication) and it may be useful to constrain the units by some valueset

# concept[].definition
The content is uncontrolled human readable text that may make sense to translate

# concept[].definition
The content has an identify and can be persisted with an appropriate life cycle such that it can be the target of a reference from a resource or another logical model