SAP patch SAPK-XXXXX* kind

I know th开发者_C百科at:

SAP_ABA  -> SAPKA?????
SAP_APPL -> SAPKH?????
SAP_BASIS-> SAPKB?????
SAP_BW   -> SAPKW?????
SAP_HR   -> SAPKE?????
SAP_CRM  -> SAPKU?????

But I don't know what SAPK-XXXXX* is. It is often applied to different components. Anybody can talk about this patch?

These package files are created using the so-called Add-On Assembly Kit (AAK). SAPK is something like the designation of the originating system (think of your normal transports, starting with K - btw, this is one of the reasons that a SID may never be "SAP", this would cause collisions here). The dash following the SAPK designates an AAK package. This is followed by a version indicator and/or a package type and/or the short package name.