Not sure how I would go about doing this in WP.. related to custom tags

There are two mechanisms in WordPress that would fit your use case: custom taxonomies and post metadata.

Since you have already determined that you want something close to mechanics to categories/tags (which are built-in taxonomies) it seems like custom taxonomy is a right fit for your use case.

See register_taxonomy() documentation on creating it.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)