Explain the problem as you see it
There is no way to highlight an information in Tana currently as a standalone block. For e.g. I was writing a note about array type in typescript and i wanted to add a special note that "number[] is different from [number].
I am migrating from logseq which has a callout, which helps me add this information inside a highlighted box so that I will know that this is some extra information. 
Why is this a problem for you?
I have been using note taking tools for the past year. I have used them mostly for taking technical notes specially related to coding. In most of the apps there is a dedicated callout or quote block to highlight some information with context to the topic or the point.
This information could be:
- a warning information like how can something go wrong.
- an important information like pay attention to this point before using.
- a note information like adding some related information but with high priority.
etc.
Suggest a solution
I was just browsing through youtube and I saw something in Capacities App, they are grouping nodes to make a group which can then be highlighted and can be used as an alternative to callouts.
Logseq is using a markdown syntax to solve this problem.