rdisp/vb2_context is a SAP Parameter attribute which is used to control Mode of update dispatching for V2 updates information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
Lets you determine how the update dispatching is done for U2 updates.
The parmeter is to be interpreted as bit mask:
Bit 0 : For dispatching the database group should be kept
Bit 1 : During dispatching, an update server must be chosen that has the
current language installed.
The default value of 3 means that an update server is selected during
update dispatching that is in the same database group and has the
current language installed.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.