A user must assign any logical name to each archive block in MS Excel. This name must be unique within all open workbooks and represents the archive block. In order to satisfy the mentioned condition, we introduce the following rule for creating the logical name of archive block:

Name of archive block (blname) consists of two parts: WB_ID and BLOCK_ID, that are separated by character "_".

• WB_ID represents a logical name of workbook in which the archive block is defined.
• BLOCK_ID is any string of characters that is unique within workbook. It is a logical name of block.