The invention relates to indexing of digitized entities in a large and comparatively unstructured data collection, for instance the Internet, such that text-based searches with respect to the data collection can be ordered via a user client terminal. Index information is generated for each digitized entity, which contains distinctive features being ranked according to a rank parameter. The rank parameter indicates a degree of relevance of particular distinctive feature with respect to a given digitized entity and is derived from fields or tags associated with one or more copies of the digitized entity in the data collection. The index information is stored in a searchable database, which is accessible via a user client interface and a search engine. The derived distinctive features and the rank parameter thus provides a possibility to carry out text-based searches in respect of non-text digitized entities, such as images, audio files and video sequences and obtain a highly relevant search result.