When registering as a seller on AliExpress, the clothing number should be filled in with the standard size of your clothing products. This is because when buying clothing, consumers usually refer to the size chart to choose the size that suits them.

If your product does not have a standard size, you can consider providing detailed size measurement data. In addition, it is recommended to fill in the relevant information carefully when registering to avoid errors or omissions in information to ensure that your store is better displayed and promoted on AliExpress.