Craig is correct here. ~= is the operator for an Indexed search.

See: Search and Indexing Administration

See also attached white paper.

Relevant intro bit:

"Laserfiche allows users to search for entries based on almost any property of the entry, from entry names and document text to metadata and creation date. For users, all searches are available in a single cohesive search interface. On the back end, however, different types of searches are performed differently by the Laserfiche Server, and it is important to understand how these searches are performed to administer your repository effectively, because different features and functionality are available for the different search methods.

The Laserfiche Server handles searches in two ways:

• Indexed searches: Indexed searches are performed by the Laserfiche Full-Text Indexing and Search Engine. Searches of document text (OCRed or extracted from individual documents) are always performed as indexed searches. Some metadata and annotation information is also indexed, and will be searched using indexed searching by default. See Indexed Searches and Indexing for more information.
• Non-indexed searches: All other searches are non-indexed searches, and are performed by the SQL search functionality of your Database Management System. In addition, with the exception of document text, all indexed searches can be performed as non-indexed searches using Advanced Search Syntax. See Non-Indexed Searches for more information."