Description
Return token as a single underscore for RFC 2047 Q encoded-text representation.
MIME encoded-words represent non-ASCII header text using a declared charset and B or Q encoding. Q encoding has special treatment for space and some punctuation; a valid local token is not necessarily a valid header in every context.
Return token as a single underscore for RFC 2047 Q encoded-text representation.
When to use this tool
Use RFC 2047 Q Space Underscore Token when checking one encoded-word or Q encoded-text component.
How to use the tool and how it works
- Enter character. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read token. Use the output convention below.
Require character to be exactly one ASCII space. Return token as a single underscore for RFC 2047 Q encoded-text representation.1
Encoded-word syntax, Q escaping and header-context restrictions are separate requirements. This tool checks only its stated local part.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| character | Character | Required. Text; maximum UTF-16 length 8192. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| token | Token | Required. Text; maximum UTF-16 length 8192. |
{
"input": {
"character": " "
},
"output": {
"token": "_"
}
}Limitations and assumptions
- This is not application/x-www-form-urlencoded or ordinary quoted-printable space handling. It does not construct a complete encoded-word or encode arbitrary text.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Alternative or Complementary methods
Use a conforming MIME header encoder for charset conversion, complete payload encoding, contextual restrictions and line folding.
References
-
Calculation and input contract: encode/rfc2047-q-space-underscore-token — tool.io
-
MIME encoded-word syntax: RFC 2047 — Internet Engineering Task Force
Similar or alternative tools
- RFC 2047 Encoded Word Charset Token
Assemble a length-bounded MIME encoded-word from supplied charset, encoding and already encoded payload text.
- Mime Q Literal Escape Choice
Emit underscore for ASCII space, a literal printable ASCII character from 33-126 except =, ? and _, or otherwise an equals sign plus uppercase two-digit hexadecimal.