The rules you seek are in EASA Part NCO.
AMC1 NCO.GEN.135(a)(10) Documents, manuals and information to be carried
ED Decision 2014/016/R
CURRENT AND SUITABLE AERONAUTICAL CHARTS
(a) The aeronautical charts carried should contain data appropriate to the applicable air traffic regulations, rules of the air, flight altitudes, area/route and nature of the operation. Due consideration should be given to carriage of textual and graphic representations of:
(1) aeronautical data, including, as appropriate for the nature of the operation:
(i) airspace structure;
(ii) significant points, navigation aids (navaids) and air traffic services (ATS) routes;
(iii) navigation and communication frequencies;
(iv) prohibited, restricted and danger areas; and
(v) sites of other relevant activities that may hazard the flight; and
(2) topographical data, including terrain and obstacle data.
(b) A combination of different charts and textual data may be used to provide adequate and current data.
(c) The aeronautical data should be appropriate for the current aeronautical information regulation and control (AIRAC) cycle.
Whilst the SD print off complies with the law, as Wrong Stuff suggests, it might be better to use the full chart and have the flexibility of utilising larger areas, especially when diversions are considered.