Background A recent study has shown that the perceived meaning of wordings in recommendations such as “should” or “must” can vary among guideline users. In addition to the wordings, many guidelines use graphic symbols such as arrows or smileys to support their recommendations.

Objectives To determine whether such symbols influence the perceived meaning of the recommendations or may help to reduce variation in the perception of the meaning between different guidelines’ users.

Methods With the help of an online-survey, using a visual analogue scale (0–100), participating physicians from different specialties were asked to express their perceived levels of obligation when confronted with different guidelines recommendations in combination with different symbols.

Results 269 physicians participated, the addition of a “single arrow” or “double arrow” to the recommendation did not lead to relevant changes in the perceived obligation expressed by the recommendation (median: soll/shall: 83 vs. 87; “sollte/should”: 77 vs. 78). In comparison to the prior study, variations in the interpretation of typical guideline wordings were not reduced if symbols were used additionally.

Discussion In this study, the impact of symbols on the understanding of a guidelines recommendation was limited. Important methodological limitations apply but this study questions the impact of symbols to clarify a recommendation’s message. However, visual aids are likely to be very important for users to help to identify recommendations within larger text document and therefore make guidelines easier to use and implement.