For most countries the most effective way of collecting the national output is via a "legal deposit" scheme. The International Conference on National Bibliographic Services (ICNBS) reaffirmed, "the value of legal deposit as a means of ensuring that the cultural and intellectual heritage and linguistic diversity of the State is preserved and made accessible for current and future users."
Legal deposit schemes may vary in their form but include:
- Statutory legal deposit
- Voluntary deposit
- Mixed deposit