Garment care labels use standardized symbols (pictograms) to provide instructions for laundering and care. These symbols are often based on ISO 3758 standard ("Textiles — Care labelling code using symbols") or similar regional standards (e.g., ASTM in USA, GINETEX in Europe). The main categories of care instructions and their basic symbols are:
- Washing: Represented by a washtub symbol. Variations indicate temperature, cycle type (gentle, permanent press), hand wash.
- Bleaching: Represented by a triangle symbol.
- An empty triangle ($\triangle$): Any bleach can be used (chlorine or non-chlorine).
- A triangle with two diagonal lines inside ($\triangle$ with //): Only non-chlorine bleach (oxygen bleach) should be used.
- A triangle crossed out ($\xcancel{\triangle}$): Do not bleach.
- Drying: Represented by a square symbol. Variations indicate tumble drying (circle inside square), line drying, flat drying, drip drying, shade drying. Dots inside tumble dry symbol indicate temperature.
- Ironing: Represented by an iron symbol. Dots inside indicate temperature setting (low, medium, high).
- Dry Cleaning (Professional Cleaning): Represented by a circle symbol. Letters inside (P, F, W, A) indicate type of solvent or process. A crossed-out circle means do not dry clean.
The question asks what the "triangle" symbol indicates on a care label. The triangle symbol specifically relates to
Bleaching instructions. \[ \boxed{\text{Bleaching}} \]