My note-organizing system: RFSR

The core principle: NO tags, ONLY links.
The co-existence of tags and links can sometimes be really confusing——you just do not know whether to use a tag or to create a note of the same name and link to it. That’s why this system throw away tags.
So all you’ll see in this system are links, links, and links. Links displayed at the top,and inline links. Links displayed at the top connect to four different kinds of node: Root node, Father node, Sibling node and Related node, which is the origin of the system’s name.
Root for reviewing specific domain.
Root should be depth-1 classification like [[Windows tips MOC]], [[Internet tips MOC]] or [[software tips MOC]].
Just use the root node that you consider is the most convenient, that is to say, you DO NOT have to set the root node to be [[computer skills]] if you think the tree [[software tips MOC]] already contains large numbers of nodes.
For example, the Root node of [[Dewey Decimal Classification]] could be [[PKM MOC]] (instead of [[library science MOC]]). DO NOT apply classification methods mechanically, if you consider [[Dewey Decimal Classification]] more as a way of PKM rather than a common practice of library science.

Father for displaying the organization structure, just like folder.
Father should be the one that best aggregate this node and its siblings, not too big, not too small.
For example, the Father node of [[Dewey Decimal Classification]] could be [[classification methods]].

Sibling for reference and comparison.
Sibling should be parallel node that belong to the same tree as this node.
For example, the Sibling node of [[Dewey Decimal Classification]] could be [[Chinese Library Classification]] and [[my own classifications]].

Related for changing the tree structure to net structure, by establishing links between distant nodes from different trees, just like tag.
Related, literally, could be any other related node. But do not pile up here, since inline mentions can be a more natural way of setting up links.
For example, the Related node of [[Dewey Decimal Classification]] could be [[how to organize notes]] and [[how to organize Obsidian]].

And here is an instance of how a single note looks like: