You specify compatibility with the plug-in API version as defined in slapi-plugin.h, which is described in Part II, Directory Server Plug-In API Reference. If you are creating a new plug-in, for example, use SLAPI_PLUGIN_CURRENT_VERSION or SLAPI_PLUGIN_VERSION_03. For example, to specify that a plug-in supports the current version, version 3, of the plug-in API, use the following:
slapi_pblock_set(pb,SLAPI_PLUGIN_VERSION, SLAPI_PLUGIN_VERSION_03);
Here, pb is the parameter block pointer passed to the initialization function. SLAPI_PLUGIN_VERSION signifies that you are setting plug-in API version compatibility in the parameter block.