165/88A is a Chinese clothing body-code label. It describes the body the garment is designed for, not a direct US letter size.
Quick answer: 165/88A means about 165 cm height, 88 cm bust or chest and standard A body type. For women's tops, it is usually close to Chinese M / US 6.
A 165/88A top is drafted for an 88 cm bust, so a 90 cm bust may feel tight.
For men's clothing, the second number usually means chest rather than bust.
The meaning of the second number depends on garment type.
The code is body-size based, while sellers may also list finished garment measurements.
This page answers one specific size search intent. For the best fit, start with the linked main converter and use the centimeter measurements on the Chinese chart whenever they are available.
Marketplace labels are useful shortcuts, but brand charts, garment type, fabric stretch and body measurements can change the final fit. Treat the lookup as a nearest match, not a guaranteed size.
Chinese size labels are practical lookup shortcuts, not universal brand guarantees. A CN shoe label, clothing size, bra code or Taobao chart row can vary by seller, product category, last shape, fabric stretch and whether the chart shows body measurements or garment measurements.
When possible, use the centimeter value first: foot length for shoes, bust/waist/hip for clothing, under-bust and cup difference for bras, and the specific Taobao chart row for marketplace listings. Then use the converter result as the nearest US, UK or EU match.
For the broader explanation, read Chinese clothing labels 160/84A to 175/96A. For why these pages give estimates instead of promises, read Chinese size chart to US complete guide.