web 2.0 applications usually have extensive tag support, for example, 2 blog articles, might have tags...

1. benz, car, honda
3. bmw, car

a good tagging system should link them up together, so when i search car, i will find articls tagged with benz, honda, bmw, etc

my initial design is:

2 tables,

tags & tag_links

tags = (1, benz), (2, car), (3, honda), (4, bmw)

tags_links = (1,2), (1,3), (2,3), (4,2)

any comments?