"大清××年制"六字两行或一行，端庄楷书。康熙、雍正朝典型，多为青花釉下。"Great Qing ×× era made" — six characters, upright regular script; typical Kangxi/Yongzheng, usually underglaze blue.

六字排成两行三列的篆书印章式，笔画匀净。乾隆朝盛行，笔力匀而板。Six characters in seal script arranged two rows of three; Qianlong-era hallmark, even and mechanical strokes.

"××年制"四字或斋堂名（如"××堂制"），多为官窑定制或文人自用，款字较小精整。Four characters, or studio/hall names (e.g. "×× hall made"); refined custom pieces, neat small script.

纹样、符号、图画款，明晚至民窑常见，非纪年款，断代意义有限。Emblem/symbol/picture marks; common in late Ming and folk kilns, not dated, limited dating value.

后朝写前朝年号（如清写"大明宣德年制"），非当时本朝，需结合胎釉青花判断。Later pieces bearing an earlier reign (e.g. Qing copying "Xuande"); date by body/glaze/blue, not the mark.