UNICHAR(): symbols as formulas
=UNICHAR(8364) → . It takes decimal code points: 176 → °, 177 → ±, 8730 → √, 9786 → ☺. Combine: =A1&UNICHAR(176)&"C" appends °C to a temperature. CHAR() is the legacy 0–255 version — always prefer UNICHAR.
Insert → Symbol and Alt codes
Insert → Symbol works per cell (double-click the cell first, or the glyph lands in the formula bar's void). Alt codes work in cells with NumLock on — Alt+0176 for °. Both paste static glyphs; fine for headers, wrong for computed data.
Custom formats: units without text
Keep numbers numeric and show units anyway: Format Cells → Custom → 0" °C", €#,##0.00, 0" ±". Values still sum and chart; the symbol is display-only. This is the correct answer to “how do I add € to a whole column”.
Why symbols break in CSV
CSV has no encoding label, so €/ñ/ü open as mojibake in the wrong reader. When saving: use “CSV UTF-8” explicitly, and when importing use Data → From Text/CSV → set File Origin to 65001: UTF-8. The glyphs were always fine — the encoding guess was wrong. See Unicode explained.