This thread will track known issues and API caveats. This is not an indicator that things will be fixed.
General- The locale query string parameter has not been implemented, thus all APIs return data in the default locale of the region.
Character Profile API- Fetching character profile data does not display the battlegroup.
- Fetching character titles returns a partially valid list.
- Fetching character titles does not highlight the selected title.
- Fetching talents does not include glyph information.
- Fetching professions may not return all professions. ... Sometimes.
- Fetching professions does not include all archaeology data.
- Statistics are not returned for characters.
- Character profiles do not include PVP information, including arena team membership and statistics.
- Fetching achievement data may contain some internal or non-public achievement data. This data will continue to be scrubbed and cleaned as needed.
Guild Profile API- Fetching guild profile data does not display the battlegroup.
- Fetching guild profile data does not display the emblem information as displayed on the character profile API.
- Fetching achievement data may contain some internal or non-public achievement data. This data will continue to be scrubbed and cleaned as needed.