The extention .gz means that the files are compressed and can be found in principle on any other format that can be compressed. another example if the .tar compression. Is fq referring to FASTQ? fastq files are simple text files you don't need any special software to view them other then a text editor like notepad,wordpad.

Thanks @Majpuc

fq indeed refers to FASTQ and it is indeed a compressed file. As far as I understand it will still need to be registered as its own content type because of the extension. Any thoughts @lzehl ?

Not sure if I understand the issue correctly.

*.*.gz is not a separate content type if the respective software does not care if it is compressed version of the file or not.
For example, the content type for NIfTI-1 has both extensions: .nii and .nii.gz

How is the behavior for .fq and .fq.gz? Do we have already a content type for FASTQ ? Maybe .fq.gz is just missing from the extensions?

I don't know for this particular extension. I just now that some sw would not open a compressed file directly and that the users will have to unzip the file before using it.

We also do not have a FASTQ content type as far as I am aware.

@lzehl Should we make a FASTQ content type here or not?

@MaaikevS sorry that I did not respond in time.
Yes we should register at least register already the generic content type for the FASTQ file format.
NOTE: we need in addition the archive specific content types that seem to exist for FASTQ (cf. https://en.wikipedia.org/wiki/FASTQ_format and intro of http://maq.sourceforge.net/fastq.shtml)