What is the function of CTRL+F, and how can I make it work?

Shortcut Keys menu provides General Hot keys and Hot Keys during voucher feeding to be used in BUSY. Thus, makes work easier and faster. Various functions can be performed using the Hot keys. On the basis of usage, we have divided Hot keys into two categories. The categories are:
 ·General Hot keys
 ·Hot keys during voucher entry
 Let us discuss various Hot keys that fall under these categories.
 General Hot keys
 F1
 Online Help
 ALT/CTRL+F1
 Add New Account
 ALT/CTRL+F2
 Add Item
 F3
 Add New Master
 ALT/CTRL+F3
 Add Voucher
 ALT/CTRL+F5
 Add Payment Voucher
 ALT/CTRL+F6
 Add Receipt Voucher
 ALT/CTRL+F7
 Add Journal voucher
 ALT/CTRL+F8
 Add Sales Voucher
 ALT/CTRL+F9
 Add Purchase Voucher
 F10
 Calculator
 ALT/CTRL+B
 Balance Sheet
 ALT/CTRL+T
 Trial Balance
 ALT/CTRL+S
 Stock Status
 ALT/CTRL+A
 Account Summary
 ALT/CTRL+L
 Account Ledger
 ALT/CTRL+I
 Item Summary
 CTRL+D
 Stock Ledger
 ALT/CTRL+G
 GST Summary
 ALT/CTRL+U
 Switch User
 ALT/CTRL+F
 Configuration
 ALT/CTRL+K
 Lock Program
 CTRL+ALT+D
 Batch Deletion of Vouchers/Masters 
 ALT/CTRL+E
 Data Export/Import
 ALT/CTRL+N
 Notes Manager
 F12
 Switch Tax Type
 Ctrl+Alt+Shift+N
 Input Implementation Notes
 Hot keys during voucher entry
 Keys
 Function
 F2
 Save Master/Voucher
 F4
 Std. Narration / BOM Help
 F5
 List of Records
 F6
 Change Voucher Type
 F7/ALT+R
 Repeat last value
 F8
 Delete Selected Master/Voucher
 F9
 Delete Selected Row in Grid
 F11
 Pick data from Orders
 ALT/CTRL+M
 Modify Master
 ALT+P
 Show Pending Batches
 ALT+O
 Show Pending Orders
 Page Up
 Previous Record
 Page Down
 Next Record
 ALT/CTRL+P
 Print Voucher/Document
 F12
 Copy Voucher/Master to clipboard
 ALT+F12
 Copy Voucher/Master from clipboard or
 Copy Voucher from XML
 ALT/CTRL+X
 Cancel/Activate Voucher
 ALT/CTRL+S
 Search a Call by Call no.