This article reports on an exploratory study aimed to identify which ways of marking required and optional fields help older people fill in web forms correctly. Drawing on a pilot study and selective attention research in ageing, modified versions of widely used forms were created, in which standard asterisks were replaced with one of three alternatives: large asterisks (double standard size), textual labels and a simple binary classification of fields. Older novice computer users participated in this study (N = 88). The quantitative results were independent of the type of form and showed that the method of denoting required fields had a significant effect on the number of errors (measured as required fields not being filled (p less than 0.05)). The participants made fewer errors in the binary classification than in the others (p less than 0.05), while the differences between standard asterisks, large asterisks and labels were not significant (p greater than 0.05). The qualitative findings revealed that the participants felt overloaded with information when using every method except the binary classification. These results challenge widespread design solutions for older people (e.g. enlarging elements) and suggest that reducing selective attention demands can help us meet their accessibility needs. (Contains 9 figures, 3 tables and 14 notes.)