Certainly not; invariant sections have the effect of limiting what modifications can be made to the work.
The GFDL also places some weird restrictions on storage and distribution of the licensed work -- notably, it forbids the use of any "technical measures to obstruct or control the reading or further copying of the copies you make or distribute". Depending on how strictly you read this, this could be interpreted as forbidding the use of encryption on filesystems containing GFDL documentation.
> Depending on how strictly you read this, this could be interpreted as forbidding the use of encryption on filesystems containing GFDL documentation.
That's a strange reading. I can see it interpreted as forbidding storing the document on a workstation that is locked-down to prevent exfiltration of sensitive data (and such a system would almost certainly also use an encrypted FS among other measures), but forbidding the use of an encrypted FS per-se seems extreme. All an encrypted FS is doing by itself is ensuring that if you don't have access to the content, then you don't have access to the content.
Nothing about the GFDL forces anyone to redistribute, it just ensures that recipients have the right to redistribute. By itself, an encrypted FS is no hindrance to redistribution.
The GFDL also places some weird restrictions on storage and distribution of the licensed work -- notably, it forbids the use of any "technical measures to obstruct or control the reading or further copying of the copies you make or distribute". Depending on how strictly you read this, this could be interpreted as forbidding the use of encryption on filesystems containing GFDL documentation.
https://wiki.debian.org/GFDLPositionStatement