Lelia is right, the required data roles is CATEGORY.    If memory serves, waaay back in SAS 9.2, the required roles were X and Y, similar to other statements like SCATTERPLOT, etc.  However, to better support the "categorizing" behavior for BARCHART,  a change was made to make CATEGORY the only required role.  In this case,  the statement will summarize the data based frequency of category.   For backwards compatibility, an alternate was provided where one could specify both CATEGORY (or X) and RESPONSE (or Y) on the left of the '/'.  Also, the CATEGORY role can be treated both as discrete or interval.  Default is discrete, and each value is placed at equal interval.  But if a chart is desired where the values are placed on the correct scale of a linear or date variable, then TYPE= can be specified on the axisopts option.   Or, in the equivalent SGPLOT procedure, XAXIS TYPE=TIME can be specified as shown in the example below: https://blogs.sas.com/content/graphicallyspeaking/2015/08/12/bar-chart-on-interval-axis-sas-9-40m3/     ... View more

The method described in the blog post Feb 02, 2016 allows you to define group values that may not be in the data, but need to be included in the legend.  Note, this same method also controls the order in which the values are displayed in the legend as described below: https://blogs.sas.com/content/graphicallyspeaking/2017/11/01/legend-order-redux/   I hope you can use this method to get the legend entries in the custom order you need. ... View more