The results and conclusions of this study are speculative in the sense that they are applications of computers (using the techniques of bioinformatics and a new predictive method), and hence they are essentially theoretical. Their role has been to highlight the likelihood that the SARS-CoV-2 spike has a biological function of binding host cell sialic acid glycans (and probably across cells surfaces by that means, as discussed below). In particular, a domain in the cap or knob of the SARS-CoV-2 spike, which has so far been somewhat neglected, is involved in the non-covalent binding of host sialic acid glycans. It is perhaps curious that subsequences found as conserved by use of bioinformatics tools such BLASTp and Clustal Omega (also used here as described in Methods Section 4.1), or detected as a known or new functional motif, often seem in the literature to be considered as having the status of experiment or observation, while consideration of more complex patterns with more sequence options tend to be treated as theory and prediction. This caution is justified in the present study because further study and confirmation is required along the lines discussed in Discussion section 5 above. above. To the extent that it is a prediction, it is a prediction for SARS-CoV-2 made in advance of experiment in order to provide an objective and fair test of the methodology and it is hoped that it will stimulate experimental study in this area whether the experiments confirm or refute that prediction. Either result would likely be of ultimate medical importance. This is essentially typical of the more interesting roles of computers in biomedical research, although the general infrastructure and support that they provide for more routine tasks is of course of great importance.