BESSER identified the underlying problem with standards that all have to struggle with in adopting a standard, namely, the tension between a very highly defined standard that is very interchangeable but does not work for everyone because something is lacking, and a standard that is less defined, more open, more adaptable, but less interchangeable. Contending that the way in which people use SGML is not sufficiently defined, BESSER wondered 1) if people resist the TEI because they think it is too defined in certain things they do not fit into, and 2) how progress with interchangeability can be made without frightening people away. SPERBERG-McQUEEN replied that the published drafts of the TEI had met with surprisingly little objection on the grounds that they do not allow one to handle X or Y or Z. Particular concerns of the affiliated projects have led, in practice, to discussions of how extensions are to be made; the primary concern of any project has to be how it can be represented locally, thus making interchange secondary. The TEI has received much criticism based on the notion that everything in it is required or even recommended, which, as it happens, is a misconception from the beginning, because none of it is required and very little is actually actively recommended for all cases, except that one document one's source. SPERBERG-McQUEEN agreed with BESSER about this trade-off: all the projects in a set of twenty TEI-conformant projects will not necessarily tag the material in the same way. One result of the TEI will be that the easiest problems will be solved--those dealing with the external form of the information; but the problem that is hardest in interchange is that one is not encoding what another wants, and vice versa. Thus, after the adoption of a common notation, the differences in the underlying conceptions of what is interesting about texts become more visible. The success of a standard like the TEI will lie in the ability of the recipient of interchanged texts to use some of what it contains and to add the information that was not encoded that one wants, in a layered way, so that texts can be gradually enriched and one does not have to put in everything all at once. Hence, having a well-behaved markup scheme is important.