To tag bookmarks just make a folder for each tag and put a symlink/alias/shortcut to the appropriate bookmarks in each tag folder.
Putting tags in the file name with a hash mark feels “ick” and like the Wrong Way to solve this problem. Using folders and symlinks goes with the “grain” of a file system based solution.
> Putting tags in the file name with a hash mark feels “ick” and like the Wrong Way to solve this problem. Using folders and symlinks [...]
I respectfully disagree. If we were speaking about millions or billions of data points, yes, performance would be important, and we would look for the "Right Way" to do it, either with a DB or with files+symlinks, as you describe.
But here simplicity and portability is key. "Title of the page #tag1 #tag2.url" does the job: easily searchable with the OS search. Why complicate this with symlinks and folders for tags for just a few 10k bookmarks?
Putting tags in the file name with a hash mark feels “ick” and like the Wrong Way to solve this problem. Using folders and symlinks goes with the “grain” of a file system based solution.