Disposition in the Harris County courts means that the case will next be set for trial or a plea - generally. Some courts allow several disposition settings which does not make sense by the definition.
In San Antonio, it means that the lawyer has told the judge the case will be resolved (usually by plea or that the State has agreed to dismiss once some pre-condition has been met). This is a great question to have him ask his attorney. Someone should understand the consequences of a plea before they take it, and it is usually good practice to have that knowledge ahead of time.
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