I am a user that migrated from stack overflow and i am very used to using ctr+k to make all my programming code there However i wonder what is the proper usage of ctr+k on this site??
The proper usage is still to indent code blocks. However, code blocks are rarely used on this site. The only use case I can think of off the top of my head would be for CSS, but there may be others.
When the site comes out of beta, we may be able to request that the code block button gets removed (UX has the Wireframe button, so it appears that some customization is allowed) but that's just conjecture so don't hold it as gospel.
Note: nobody is suggesting removal at this point, I just included that since we were on the topic of GD's UX and how it may differ from other sites in the network.