Splitting long strings in RRs using parentheses

[Sandro]

Hello,

While adding a DKIM key to my zone I was looking for information about 
using parentheses for working around the string length limitation.

I looked at the way BIND puts them in my zone file for RRSIG entries and 
and applied that to the TXT record:

20220317-a4qe._domainkey    TXT (
	v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAA
         OCAQ8AMIIBCgKCAQEAmEsWuQCj+OenaSQ3dM6WItExor
         ...
         QXLXEHkQIDAQAB )

However, that was transformed by BIND into:

20220317-a4qe._domainkey.penguinpee.nl.	3600 IN	TXT
"v=DKIM1" "OCAQ8AMIIBCgKCAQEAmEsWuQCj+OenaSQ3dM6WItExor"
...
"QXLXEHkQIDAQAB"

The bit from the first semicolon to the end of the line was missing.

Is that expected behavior? I couldn't find any documentation regarding 
the usage of parentheses. I know I can also use multiple strings, just 
like in the answer from BIND.

I worked around the issue defining it as follows:

20220317-a4qe._domainkey    TXT "v=DKIM1; k=rsa; " (
          p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQ

That returns the full key and all parameters. So, this question is more 
out of curiosity.

-- Sandro