Tags are what WordPress calls is keywords. I attach a small number of tags to every post to help people navigate between content with the same keywords. Tags may be people (David Gauke say), organisations (The Howard League, Revolving Doors Agency), themes (women offenders, homelessness) or specific items (heroin, cocaine, ROTL). If you’re looking to research a particular issue, they can be invaluable.
The reason for targeting health interventions at offenders is that poor health is often interlinked with offending. Offenders are known to suffer disproportionately from multiple and complex health issues which are often exacerbated by the difficulties they experience in accessing health and social care services in the local community.