Proposal for reviving an old General Semantics notation: borrowing from scientific writing and using subscripts like ‘Gwern₂₀₂₀’ for denoting sources (like citation, timing, or medium). Using subscript indices is flexible, compact, universally technically supported, and intuitive. This convention can go beyond formal academic citation and be extended further to ‘evidentials’ in general, indicating the source & date of statements. While (currently) unusual, subscripting might be a useful trick for clearer writing, compared to omitting such information or using standard cumbersome circumlocutions.