Buildings in Islamic architecture are characterized in general, in employing written inscriptions in many aspects of the building; as the external elements (facades, entrances, minarets, domes ...) as well as the internal elements of the building (mihrabs, minbars, columns, walls and ceilings of the Interior…).
Employing written inscriptions has many characteristics which can be classified into two groups: the first are related to the architectural aspects, as position within the building, method of execution, building materials, the second group are related to aspects of Fine Art for the calligraphy as type of font, size and proportion ...Both characteristics contributed to enhancing the various functions provided by this writings as defining the building, and its creator, or its symbolic significance of meaning according to building type or inscriptions' position or theme.
The research aims to detect and identify design characteristics of employing inscriptions within the architecture of the Congregational mosques and Multifunctional complexes (Which include the addition of a school or Mausoleum, or both at the mosque) which are related architectural aspects, and to show dissimilarity of those characteristics depending on the local styles within Islamic architecture, in order to come up with recommendations to help implementing this knowledge in future designs of contemporary Islamic architecture.

Keywords: Islamic architecture, written inscriptions, Arabic calligraphy.