Typically a short and unique identifier, such as a SKU number, possibly with some sort of suffix, such as if a SKU has multiple images or has locale-specific variations. May also be a more complex string which looks more like a file path, to support easy retrofitting of web sites with Image Serving.
The image and SVG tables are merged into a single table when the image catalog is loaded. Id values must be unique across both tables. The SVG record is discarded if the image table contains a record with the same ID value. Static content is managed with a separate table; static content items and image/SVG items may thus have the same Id values.
Text string. Required. Record identifier for the image/SVG or static content data table. Each catalog::Id value within this image catalog/SVG catalog or within this static content catalog must be unique and must not include ',' characters.