avatech-multitier Schema for an AVATecH multitier file, which allows to use independent segmentations in different tiers within a single XML file. In a single tier format, it is possible to store multiple tiers, but with only one time segmentation which had to be shared by all tiers.each item describes a timespan, with start time and end time. Times in each tier item have to be in ascending order and the timespans must not overlap. They can, however, be back to back. Content can be free text, numerical values, text using a controlled vocabulary or similar. Of course all spans must provide values (v) for all columns and the values must be given in the same order as specified in the columns header attribute. development AVATecH avatech-multitier.xsd