Alphanumeric Identifier
representation.identifier.alphanumeric_idMixed letter-and-digit identifier string that doesn't match a known specific format. Examples: product codes ("SKU-12345"), cabin numbers ("C85"), ticket IDs ("A/5 21171"), lot numbers ("LOT-2024-0042"), license plates ("ABC 1234"). Format-detectable: contains both alphabetic and numeric characters.
Worked samples
DuckDB 1.5.5 · finetype 0.6.64
| Value | As VARCHAR | alpha_part | numeric_part |
|---|---|---|---|
| SKU-12345 | SKU-12345 | SKU | 12345 |
| C85 | C85 | C | 85 |
| A/5 21171 | A/5 21171 | A | 5 |
| LOT-2024-0042 | LOT-2024-0042 | LOT | 2024 |
| ABC 1234 | ABC 1234 | ABC | 1234 |
| REF-00742 | REF-00742 | REF | 00742 |
| B28 | B28 | B | 28 |
| FL-2087 | FL-2087 | FL | 2087 |
Shape
^[A-Za-z][A-Za-z0-9 /_.#-]*[0-9][A-Za-z0-9 /_.#-]*$|^[0-9][A-Za-z0-9 /_.#-]*[A-Za-z][A-Za-z0-9 /_.#-]*$| Value | Length | Shape |
|---|---|---|
| SKU-12345 | 9 | matches |
| C85 | 3 | matches |
| A/5 21171 | 9 | matches |
| LOT-2024-0042 | 13 | matches |
| ABC 1234 | 8 | matches |
| REF-00742 | 9 | matches |
| B28 | 3 | matches |
| FL-2087 | 7 | matches |
Told apart
Going the other way, this type's own rule accepts 3 of 3 samples of UUID.
Background
Origin
FineType defines the Alphanumeric Identifier type itself, to catch mixed letter-and-digit identifiers that fall through more specific types such as UUID, ISIN and IATA codes.[1] FineType's validation pattern for the type requires at least one letter and at least one digit.[1]
Use
Microsoft Excel, with default settings, is known to convert gene names to dates and floating-point numbers.[2] A programmatic scan of leading genomics journals found that approximately one-fifth of papers with supplementary Excel gene lists contained erroneous gene name conversions.[2] Microsoft's support documentation says Excel automatically removes leading zeros and converts large numbers to scientific notation.[3]
The ELF code in GLEIF's ISO 20275 Entity Legal Forms code list is an alpha-numeric code of four characters from the basic Latin character set.[4] Before settling on a generic label for a column of short mixed codes, check whether the codes belong to a published scheme such as the ELF list, since a published list can be validated value by value. (Meridian's view)
Where you'll meet it
In a published copy of the Titanic passenger dataset, the Ticket column mixes values such as A/5 21171 and PC 17599 with plain numbers such as 113803.[5] The Titanic passenger file's Cabin column holds codes such as C85 and C123.[5] A ticket column like the Titanic one shows that a single field can hold several identifier shapes at once, so a profile of mixed codes is worth reading row by row before you trust it. (Meridian's view)
Sources
- [1]finetype/labels/definitions_representation.yaml at main · meridian-online/finetype · GitHubFineType
- [2]Gene name errors are widespread in the scientific literaturesecondary source
- [3]Keeping leading zeros and large numbersdocumentation
- [4]ISO 20275: Entity Legal Forms Code List - Code Lists - LEI Data – GLEIForganisation
- [5]titanic.csvdataset
Detection notes
Moved from representation.code.alphanumeric_id in v0.5.1. Catches mixed letter+digit identifiers that fall through more specific types (UUID, ISIN, IATA, etc.). The validation pattern requires at least one letter AND one digit. Format-detectable.
In Meridian's open data
- gleif
legal_formconfidence 0.6
Use it
$ finetype infer -i "SKU-12345" --mode column
→ representation.identifier.alphanumeric_id
SELECT ft_infer('SKU-12345');
-- → 'representation.identifier.alphanumeric_id'CAST({col} AS VARCHAR)Schema
https://meridian.online/schemas/representation.identifier.alphanumeric_id · Frictionless type string
finetype taxonomy representation.identifier.alphanumeric_id -o json-schema