Description
Check one supplied VIN-position character against the accepted uppercase alphabet and forbidden I/O/Q set.
Identifier validation can involve several distinct questions: whether text has the expected shape, whether a checksum is consistent, and whether an authority actually assigned the identifier. Formatting and field extraction address narrower questions. Each result must be read according to the particular property the tool checks.
Check one supplied VIN-position character against the accepted uppercase alphabet and forbidden I/O/Q set.
When to use this tool
Use Vin Forbidden Letter Single Position Flag when you need the particular shape, formatting, field, or checksum property as one explicit stage in an identifier workflow.
How to use the tool and how it works
- Enter character, position. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read allowed, forbidden. Inspect allowed, forbidden before interpreting the associated values.
Require position from one through 17. Return allowed only for one uppercase letter or digit in the implemented VIN alphabet and forbidden only for the exact letters I, O, or Q.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| character | Character | Required. Text; maximum UTF-16 length 8192. |
| position | One-based position from one through 17; does not alter the alphabet check. | Required. Safe integer; minimum 1; maximum 17. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| allowed | Allowed | Required. Boolean. |
| forbidden | Forbidden | Required. Boolean. |
{
"input": {
"character": "I",
"position": 5
},
"output": {
"allowed": false,
"forbidden": true
}
}Limitations and assumptions
- Position does not change the alphabet test. Lowercase or multi-character inputs can be neither allowed nor forbidden; this does not validate a complete VIN, check digit, manufacturer code, or vehicle identity.
- The field tables state structural bounds; the mechanics also specify cross-field constraints. Malformed inputs and unsupported domains cause errors. A successful false flag, empty branch value, or zero placeholder has the meaning stated above and is distinct from an input error.
Alternative or Complementary methods
Use a complete format and checksum validator when required, then consult the issuing registry or verification process for assignment and identity. Preserve meaningful leading zeros as text.
References
Similar or alternative tools
- Check Digit Position Contract
Inspect an explicit check-digit position convention without computing or validating a checksum.
- Validation: DOI Prefix Single Field Check
Check the commonly specified DOI registrant-prefix lexical shape only, without validating a suffix, registration or resolution.