---
name: "Catmandu::Fix::issn"
section: "3pm"
platform: "linux"
package: "libcatmandu-identifier-perl"
version: "0.15-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Catmandu::Fix::issn"
---

# Catmandu::Fix::issn(3pm)

normalize the issn value for a given key

## NAME

Catmandu::Fix::issn - normalize the issn value for a given key

## SYNOPSIS

```
  # Normalize the ISSN value of issn_field.
  # e.g. issn_field => '1553667x'
  issn(issn_field) # issn_field => '1553-667X'
```

## SEE ALSO

Catmandu::Fix