(pos:名詞)
<explanation>
yue:新#郵票 發行嘅第一日，將郵票貼喺特製信封右上角，加埋當日郵政日戳或特別紀念郵戳嘅信封（量詞：個）
eng:(of philately) first day cover
<eg>
yue:我好鍾意收集首日封，因為我覺得好有紀念價值。 (ngo5 hou2 zung1 ji3 sau1 zaap6 sau2 jat6 fung1, jan1 wai6 ngo5 gok3 dak1 hou2 jau5 gei2 nim6 gaa3 zik6.)
eng:I love to collect first day covers, as I believe that they've got sentimental value.