noun
DX code
A barcode-like pattern on 35mm film cassettes used by cameras to automatically set film speed (ISO).
このフィルムにはＤＸコードが付いているので、カメラが自動的にISO感度を読み取ります。
This film has a DX code, so the camera automatically reads the ISO speed.
Standard full-width alphanumeric spelling.
Half-width variant commonly seen in technical contexts.
From English 'DX code', where DX is an abbreviation of 'Digital indeX'.