This Recommendation contains a guide to CE aspects, parameters, metrics, indicators for ICT based on current approaches, concepts and metrics of the Circular Economy (CE) as defined in existing standards, while considering their applicability for ICT. In the present document ICT is defined as based on OECD [b-ISIC]. This Recommendation discusses the special considerations and challenges for all ICT of defining parameters, metrics, and indicators broader and in more depth than before. This document intends to guide the vertical standardization of material efficiency for ICT. The guideline intends to investigate what kinds of standards are available and relevant for what ICT product groups. Examples of interrelated relevance is mentioned throughout the text of the Recommendation. As such, this Recommendation precedes a potential vertical standardization of specific ICT product groups, but follows up on existing understanding of the whole ICT sector. In this sense the presumed vertical standardization of ICT product groups is intended to benefit from this document.