CJK Unified Ideograph-9E30

It names a wagtail-type bird and, in an old allusion, brotherly help.

Originally the character wrote a bird name: 令 gives the sound, 鳥 marks the bird. The oldest literary trail in the Book of Songs is the line 脊令在原, where brothers face danger together. Later compounds — 鶺鴒/鹡鸰 and 鸰原 — carry that image into literary Chinese. For the glyph itself, the earliest concrete form in the Tang Kaicheng Stone Classics is 鴒; later dictionary forms follow. The consulted sources do not identify a single inventor.

What does 鸰 mean when someone sends it?

Usually, the surrounding word decides whether it is literal or allusive.

Read a bare 鸰 as a bird-name lookup, not a mood marker. In 鸰原 or 鶺鴒在原 it invokes brothers helping one another; in Japanese, 鴒 is chiefly met inside 鶺鴒, the wagtail name セキレイ. Readers who know classical Chinese may catch the allusion; others see only a bird character. Send the full compound when you need the fraternal reading to land.

Check the script and the font before decoding it

鸰 and 鴒 are simplified and traditional forms of the same character. A font can alter stroke detail or fail to draw the glyph, so a box or odd shape is not a new meaning. Match the script of the surrounding text; do not replace it with 令, which is only the sound component here.