1. Unable to query fields that start with a number.
Details: Field names that start with a number (for example, "2005Field") are truncated to include the number only (for example, "2005").
Workaround: Enclose fields that start with a number in square brackets (for example, "[2005Field]").
2. Query for long-text fields that contains SQL noise words will return empty result without any error.
Details: When you use the Contains operator to query a long-text field, work item tracking performs a SQL Server full-text query on the work item database. The full-text query excludes SQL noise words such as “a”, “of” and non-alphanumeric characters. An empty result list is returned when you use this kind of query that contains SQL noise words.
Workaround: Remove SQL noise words from the query.