saey-context-models-dna-base64-arabic-hebrew

Summary

The system decides whether a string of characters "belongs" to a given format by checking it against a fixed alphabet or range. For example, a valid DNA sequence can only contain the four letters A, T, C, and G, a base64 payload is limited to letters, digits, and the plus and slash symbols, and Arabic or Hebrew text is recognized by whether its code points fall inside specific Unicode blocks. In practice, this is the ground-level rule the system uses to say yes or no when asking "is this piece of data actually in the format you claim it is?"