Indexing as a practice
Indexing is a useful practice for large piles of information. Manually indexing invites us to look for patterns, cull old information, and help us reflect on what's most important.
Visakanv on indexing:
Making lists is a powerful practice
Making information more accessible makes it more useful. Similar to linking in information architecture. You can see an example of how he approaches indexing here: https://www.visakanv.com/blog/threads/ and this: https://www.visakanv.com/blog/ref/