# IGSN identifier

An IGSN identifier (or IGSN ID) is a type of [handle system](https://en.wikipedia.org/wiki/Handle_System)
handle that takes the form of a string divided into two parts (prefix and suffix),
separated by a slash:

```text
prefix/suffix
```

The *prefix* identifies a repository and thus also the registrant of the identifier.
It is usually in the form `10.XXXX`, where `XXXX` is at least a four-digit number
greater than or equal to 1000. The `10` in the prefix identifies the handle as part
of the DOI namespace, as opposed to another handle system namespace.

The *suffix* is chosen by the registrant and identifies the specific sample linked
to the IGSN.

Most permissible Unicode characters are allowed in prefix and suffix, which are interpreted
independently of upper and lower case.

**Example:**

For the IGSN ID `10.58030/kielbot0007007` the prefix is `10.58030` and the suffix
is `kielbot0007007`.

## How to display IGSN IDs

:::{note}
The display guidance is based on [DataCite's best practices](https://support.datacite.org/docs/registering-igsn-ids-1#displaying-igsn-ids).
:::

### IGSN ID long display form

Like DOIs, the canonical form of an IGSN ID is a complete [https://doi.org/](https://doi.org/)
URL using the form:

```text
https://doi.org/10.58030/kielbot0007007
```

See [DataCite IGSN Display Guidelines](https://support.datacite.org/docs/displaying-igsn-ids)
for more information about displaying IGSN IDs.

### IGSN ID short display form

IGSN IDs are sometimes displayed in locations where a complete [https://doi.org/](https://doi.org/)
URL is not appropriate. In these cases, IGSN IDs should be displayed with only the
DOI prefix and suffix:

```text
igsn:10.58030/kielbot0007007
```

:::{note}
The short display form should be typically preceded by an `igsn:` tag to specify
that it is an IGSN ID. However, in cases where IGSN IDs are already clearly denoted,
such as in the column header of a data table, the preceding `igsn:` tag may be excluded
from the short display form.
:::

### Hyperlinking IGSN IDs

Where possible, all representations of IGSN IDs should be hyperlinked with the IGSN
ID's complete DOI link. For example, [https://doi.org/10.58030/kielbot0007007](https://doi.org/10.58030/kielbot0007007).

### IGSN IDs in metadata

IGSN IDs encoded in metadata should contain the IGSN ID’s complete DOI URL. This
includes IGSN IDs entered in DataCite Metadata Schema properties such as `relatedIdentifier`.

### QR codes

QR codes for IGSN IDs should contain the complete DOI URL. For example, [https://doi.org/10.58030/kielbot0007007](https://doi.org/10.58030/kielbot0007007).

If a QR code is applied to a sample or its container, the label should also display
the IGSN ID short display form in a human-readable way.