Symbol Loading Units ( SLU):

Why in News? The Supreme Court on Friday directed the Election Commission of India (ECI) to “seal and secure” the Symbol Loading Unit (SLU) for 45 days after the declaration of election results.

Currently, only the three components of the EVM — the ballot unit, control unit, and VVPAT — are stored for 45 days after the results. This is the first time that SLUs, used to load candidate symbols onto the VVPATs, will also be available for examination along with the EVMs if a candidate challenges the results by filing an election petition in court.
What is a Symbol Loading Unit (SLU) and how does it work?
Symbol Loading Units (SLUs) were introduced around the same time as VVPATs — a little over a decade ago. VVPATs help voters verify their votes — they see a slip with a printed image of the party symbol they voted for.

But for the VVPAT to print a symbol correctly, information pertaining to the list of candidates and their symbols must be loaded on to the VVPAT machine in the correct order. This is where the Symbol Loading Unit, or SLU, comes in. In fact, the introduction of VVPATs necessitated the use of SLUs.

The SLU is used to load the symbols of the candidates onto the VVPAT. It is a matchbox-sized device that is first connected to a laptop or personal computer, from where a symbol loading application is used to load a bitmap file containing the candidates’ names, serial numbers, and symbols.
What has the SC said about the SLUs?
The court has said that the SLUs should be sealed and stored immediately after the symbol-loading process for a seat is complete. It must be stored for a period of 45 days after the declaration of results, so that it can be opened and examined like EVMs in case of an election petition.

This effectively means that an SLU used for loading symbols onto VVPATs for one seat can no longer be reused for other seats. Consequently, the EC will need more SLUs. Sources said the Commission currently has about 5,000 SLUs, and will need an additional 2,000 to implement the SC’s direction.
What changes on the ground?
Nothing changes for the voter. However, a lot changes in the way the ECI organises polling.

The ECI will now have to store SLUs for 45 days after voting. To reserve one SLU exclusively for one seat, it will need to order more SLUs. It will also have to ensure the verification of EVMs upon request from candidates who finish second or third, which may require additional manpower.
Also, the ECI will have to examine whether the Representation of the People Act of 1951 has to be amended. The election law currently states that an election petition challenging a result can be filed in court by a candidate within 45 days of the declaration of results. During this period, the EC machinery does not touch the EVMs. If these machines now need to be unsealed for verification purposes, the poll panel will have to determine how this can be accomplished