noun
third-class mail
A category of postal item under Japan Post's classification system, typically used for periodicals and certain publications sent at reduced rates.
この雑誌は第三種郵便物として発送されています。
This magazine is dispatched as third-class mail.
Standard kanji spelling using the numeral 三.
Variant using the half-width digit ３; commonly seen in official documents and forms.
Compound of 第三種 (third class) + 郵便物 (mail item). The term is a direct description of its postal classification.