The longer answer is, you might be able to do it with a CSS snippet, but probably with side effects. Like, you could make all callouts inline, or all callouts in any note that has a certain class assigned to it (using the “cssclasses” property).
If you just want short snippets of text, like an IP address, you could consider using dataview and fields.
Given something like ip: 192.168.1.1 in the frontmatter of a file named “MyData” (which of course can be whatever name you want), you could use `$= dv.page("MyData").ip ` in your current file to retrieve that information.