Description
Join explicit nonempty MIME subtype and structured-suffix tokens with one plus; caller verifies registration, no serialization of a complete Content-Type.
A media type has a type/subtype token and may carry named parameters. Multipart content uses explicit boundary delimiter lines around its parts. Token case rules, parameter quoting, repeated records and exact line endings affect how a representation is interpreted; a lexical check is narrower than parsing a complete message.1
Join explicit nonempty MIME subtype and structured-suffix tokens with one plus; caller verifies registration, no serialization of a complete Content-Type.
When to use this tool
Use this tool to join explicit nonempty MIME subtype and structured-suffix tokens with one plus; caller verifies registration, no serialization of a complete Content-Type.
How to use the tool and how it works
- Enter base, suffix using the field definitions below.
- Run the operation. Correct input errors before interpreting an output.
- Read result.subtype. Use the ordering, boundary rules and absence conditions described below.
Require token-safe base and suffix and prohibit a plus inside suffix, then join them with one plus.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| base | Token-safe subtype base before the appended plus. | Text, at most 8,192 UTF-16 code units; the operation’s grammar also applies. |
| suffix | Token-safe suffix without an internal plus. | Text, at most 8,192 UTF-16 code units; the operation’s grammar also applies. |
| Output field | Interpretation |
|---|---|
| result | Object containing the named fields below. |
| result.subtype | Normalized subtype or constructed base-plus-suffix token. |
{
"input": {
"base": "problem",
"suffix": "json"
},
"output": {
"result": {
"subtype": "problem+json"
}
}
}Limitations and assumptions
- This constructs a subtype token without validating a registered media type or suffix semantics.
- Supported boundary strings contain 1–70 characters from the declared MIME boundary subset and cannot end in a space. Single-byte envelope budgets are distinct from UTF-8 text byte counts and from a complete MIME transport.
- Every declared top-level input field is required and unexpected fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
- Numeric outputs must be finite and no larger in absolute magnitude than the safe-integer limit; operations returning exact large integers use decimal text. Positions are zero-based and spans end exclusively unless the operation explicitly states a different convention.
Alternative or Complementary methods
Choose the target media-type and multipart conventions explicitly. Use a complete MIME parser for nested messages and encodings; these record and delimiter tools handle only their stated representations.
References
-
RFC 2046: MIME Media Types — RFC Editor
-
Tool behavior and example: Media Type Suffix Token Join — tool.io
Similar or alternative tools
- Media Type Offer Specificity Order
Stable-order bare MIME ranges by exact/type-wildcard/all-wildcard specificity only; excludes qualities, parameters and offer preference.
- Media Type Parameter Conflict Table
Audit conflicting decoded MIME parameter values under case-insensitive names and case-sensitive literal values; no registered-parameter equivalence inference.