Hi,
There is no standard authorization object for special stock. you have to develop Z object for field of SOBKZ with help of ABAPER.
For Migo available authorization objects are :
| A_B_ANLKL | Asset Postings: Company Code/Asset Class |
| A_B_BWART | Asset Postings: Asset Class/Transaction Type |
| B_USERST_T | Status Management: Set/Delete User Status using Transaction |
| B_USERSTAT | Status Management: Set/Delete User Status |
| C_AFKO_AWK | CIM: Plant for order type of order |
| C_CACL_DSG | Interface Design |
| C_DRAW_BGR | Authorization for authorization groups |
| C_DRAW_DOK | Authorization for document access |
| C_DRAW_TCD | Authorization for document activities |
| C_DRAW_TCS | Status-Dependent Authorizations for Documents |
| C_KLAH_BKP | Authorization for Class Maintenance |
| C_STUE_BER | CS BOM Authorizations |
| C_STUE_WRK | CS BOM Plant (Plant Assignments) |
| C_TCLA_BKA | Authorization for Class Types |
| C_TCLS_BER | Authorization for Org. Areas in Classification System |
| C_TCLS_MNT | Authorization for Characteristics of Org. Area |
| CPE_SETTIN | Commodity Pricing Engine: General Settings |
| F_BKPF_BUK | Accounting Document: Authorization for Company Codes |
| F_BKPF_BUP | Accounting Document: Authorization for Posting Periods |
| F_BKPF_KOA | Accounting Document: Authorization for Account Types |
| F_FICA_FOG | Funds Management: Authorization Group of Fund |
| F_FICA_FPG | Funds Management: Authorization Group for Commitment Item |
| F_FICA_FSG | Funds Management: Authorization Group for Funds Center |
| F_FICB_FKR | Cash Budget Management/Funds Management FM Area |
| F_KNA1_APP | Customer: Application Authorization |
| F_LFA1_APP | Vendor: Application Authorization |
| F_SKA1_BUK | G/L Account: Authorization for Company Codes |
| FI_WEI_BUK | Real Estate: Business entity - Authoriz. for CoCd/BE |
| G_GLTP | Spec. Purpose Ledger Database (Ledger, Record Type, Version) |
| J_1IDEP_SL | Authorization object for depot sale transaction |
| J_1IEX_PST | Autorization object for posting Other Excise invoice |
| J_1IEXC_OT | Authorization object for Other Excise Invoice Create |
| J_1IGRPT1 | Auth. for PART1 at GR |
| J_1IINEX | Incoming Excise Invoice |
| J_1IRG23D | Authorisation object for Depo Transactions |
| K_AUFK_ART | CO-OPA: Order Types |
| K_CCA | CO-CCA: Gen. Authorization Object for Cost Center Accounting |
| K_CSKS | CO-CCA: Cost Center Master |
| K_CSKS_SET | CO-CCA: Cost Center Groups |
| K_ORDER | CO-OPA: General authorization object for internal orders |
| K_PCA | EC-PCA: Responsibility Area, Profit Center |
| L_TCODE | Transaction Codes in the Warehouse Management System |
| M_ANFR_BSA | Document Type in RFQ |
| M_ANFR_EKG | Purchasing Group in RFQ |
| M_ANFR_EKO | Purchasing Organization in RFQ |
| M_ANFR_WRK | Plant in RFQ |
| M_BEST_BSA | Document Type in Purchase Order |
| M_BEST_EKG | Purchasing Group in Purchase Order |
| M_BEST_EKO | Purchasing Organization in Purchase Order |
| M_BEST_WRK | Plant in Purchase Order |
| M_EINF_EKO | Purchasing Organization in Purchasing Info Record |
| M_MATE_CHG | Material Master: Batches/Trading Units |
| M_MATE_MAN | Material Master: Data at Client Level |
| M_MATE_STA | Material Master: Maintenance Statuses |
| M_MATE_VKO | Material Master: Sales Organization/Distribution Channel |
| M_MATE_WRK | Material Master: Plants |
| M_MRES_BWA | Reservations: Movement Type |
| M_MRES_WWA | Reservations: Plant |
| M_MSEG_BMB | Material Documents: Movement Type |
| M_MSEG_BWA | Goods Movements: Movement Type |
| M_MSEG_BWE | Goods Receipt for Purchase Order: Movement Type |
| M_MSEG_BWF | Goods Receipt for Production Order: Movement Type |
| M_MSEG_LGO | Goods Movements: Storage Location |
| M_MSEG_WMB | Material Documents: Plant |
| M_MSEG_WWA | Goods Movements: Plant |
| M_MSEG_WWE | Goods Receipt for Purchase Order: Plant |
| M_MSEG_WWF | Goods Receipt for Production Order: Plant |
| M_RAHM_BSA | Document Type in Outline Agreement |
| M_RAHM_EKG | Purchasing Group in Outline Agreement |
| M_RAHM_EKO | Purchasing Organization in Outline Agreement |
| M_RAHM_WRK | Plant in Outline Agreement |
| Q_TCODE | QM Transaction Authorization |
| S_ADMI_FCD | System Authorizations |
| S_ALV_LAYO | ALV Standard Layout |
| S_APPL_LOG | Applications log |
| S_BDS_DS | BC-SRV-KPR-BDS: Authorizations for Document Set |
| S_BTCH_ADM | Background Processing: Background Administrator |
| S_BTCH_JOB | Background Processing: Operations on Background Jobs |
| S_CTS_ADMI | Administration Functions in Change and Transport System |
| S_DATASET | Authorization for file access |
| S_DEVELOP | ABAP Workbench |
| S_DOKU_AUT | SE61 Documentation Maintenance Authorization |
| S_GUI | Authorization for GUI activities |
| S_HIERARCH | Hierarchy maintenance authorization check |
| S_OC_DOC | SAPoffice: Authorization for an Activity with Documents |
| S_OC_ROLE | SAPoffice: Office User Attribute |
| S_OC_SEND | Authorization Object for Sending |
| S_OC_TCD | SAPoffice: Transaction Code Authorizations |
| S_PACKSTRU | Internal SAP Use: Package Structure |
| S_PRO_AUTH | IMG: New authorizations for projects |
| S_PROJECT | Project Management: Project authorization |
| S_RFC | Authorization Check for RFC Access |
| S_SCD0 | Change documents |
| S_SPO_DEV | Spool: Device authorizations |
| S_TABU_DIS | Table Maintenance (via standard tools such as SM30) |
| S_TCODE | Transaction Code Check at Transaction Start |
| S_TRANSLAT | Translation environment authorization object |
| S_TRANSPRT | Transport Organizer |
| S_WFAR_OBJ | ArchiveLink: Authorizations for access to documents |
| V_LIKP_VST | Delivery: Authorization for Shipping Points |
| V_VBAK_AAT | Sales Document: Authorization for Sales Document Types |
| V_VBAK_VKO | Sales Document: Authorization for Sales Areas |
| W_VKPR_WRK | IS-R Authorization: SP Calculation: Distr. Chain/Plant |
| W_WBRK_FKA | ISR Trading: authorization for vendor billing document type |
| W_WBRK_ORG | ISR Trading: Authorization for organizational data |