Minimum and Maximum

The minimum and maximum constraints restrict the allowed range or size of a node. Both constraints are inclusive, meaning the boundary values themselves are considered valid.

Depending on the node type, these constraints apply to numeric values, textual lengths, collection sizes, or structural dimensions.

Type Matrix

The following table summarizes which node types support minimum and maximum and how the constraint values are interpreted.

Node Type	Value Type	Details
Integer	Integer	Constrains the minimum and maximum allowed integer value.
Boolean
Float	Float	Constrains the minimum and maximum floating-point value. If any bound is defined, `NaN` is disallowed. If a bound excludes positive or negative infinity, `+Inf` or `-Inf` is disallowed accordingly.
Text	Integer	Constrains the number of Unicode code points (characters).
Date	Date	Constrains the earliest and/or latest valid date.
Time
DateTime	DateTime	Constrains the earliest and/or latest valid date-time.
Bytes	Integer	Constrains the number of bytes.
TimeDelta
RegEx
Value
ValueList	Integer	Constrains the minimum and maximum number of list elements.
ValueMatrix	ValueList Integer	Constrains the minimum and maximum number of rows and columns. The first integer applies to rows, the second to columns.
Section	Integer	Constrains the number of child entries when using `vr_any`.
SectionList	Integer	Constrains the number of entries in the section list.
SectionWithTexts	Integer	Constrains the number of child entries when using `vr_any`.
NotValidated

Rules for Minimum and Maximum

Inclusive Boundaries: Both minimum and maximum are inclusive. A value equal to the specified boundary is valid.

[server.min_port]
type: "integer"
minimum: 1
maximum: 65534

[server.max_port]
type: "integer"
minimum: 1
maximum: 65534

[server]
min_port: 1      # VALID: equals minimum
max_port: 65534  # VALID: equals maximum

Type-Specific Semantics: The value type of minimum and maximum must match the semantic meaning of the node type:
- For numeric types, the constraint limits the numeric value.
- For text, the integer represents the number of Unicode code points.
- For bytes, the integer represents the number of bytes.
- For lists, sections, and matrices, the integer represents the number of contained entries.
```
[client.username]
type: "text"
minimum: 3   # At least 3 characters
maximum: 12  # At most 12 characters
```
Special Values for Floats: If either minimum or maximum is defined for a float node, NaN values are not permitted.

Likewise, +Inf or -Inf are not permitted if they fall outside the specified bounds.
```
[client.ratio]
type: "float"
minimum: 0.001
```
```
[client]
ratio: NaN  # ERROR: NaN is not allowed when bounds are defined
```
Matrix Constraints: For ValueMatrix nodes, minimum and maximum accept two integers.

The first integer constrains the number of rows, and the second constrains the number of columns.
```
[app.matrix]
type: "ValueMatrix"
minimum: 2, 3   # At least 2 rows and 3 columns
maximum: 5, 8   # At most 5 rows and 8 columns
```
Invalid Combinations: If both minimum and maximum are defined, validators must verify that minimum ≤ maximum.

If this condition is violated, the Validation Rules document itself is invalid.
```
[server.port]
type: "integer"
minimum: 100
maximum: 10  # ERROR: minimum is greater than maximum
```

Examples

Numeric Limits

[server.port]
type: "integer"
minimum: 1
maximum: 65534

[server]
port: 8080  # VALID

[server]
port: -1  # ERROR: Must be in the range 1–65534

Text Limits

[client.username]
type: "text"
minimum: 1
maximum: 32

[client]
username: "example"  # VALID

[client]
username: ""  # ERROR: Must contain at least 1 character