---input---
RFC 1
RFC 2
RFC 3f
rfc 4
PMID      114514
ISBN 978-3-16-148410-0
ISBN 978 3 16-148410 0
https://example.com
irc://example.com
nolink://example.com

---tokens---
'RFC 1'       Name.Function.Magic
'\n'          Text

'RFC 2'       Name.Function.Magic
'\n'          Text

'RFC'         Text
' '           Text
'3f'          Text
'\n'          Text

'rfc'         Text
' '           Text
'4'           Text
'\n'          Text

'PMID      114514' Name.Function.Magic
'\n'          Text

'ISBN 978-3-16-148410-0' Name.Function.Magic
'\n'          Text

'ISBN 978 3 16-148410 0' Name.Function.Magic
'\n'          Text

'https://example.com' Name.Label
'\n'          Text

'irc://example.com' Name.Label
'\n'          Text

'nolink'      Text
':'           Text
'/'           Text
'/'           Text
'example'     Text
'.'           Text
'com'         Text
'\n'          Text