Short term capital loss

1. No.

2. By filing ITR within due date, any un-adjusted Loss can be carried forward for adjustment against same head.

1. Loss under the head Capital gains is dealt under sec 74. Any loss under the head Capital gains should be adjusted only against gains arising under this head. (inter head adjustments are not allowed ). However Long term capital loss can only be set off against long term capital gains.   
2. In your case, STCL from the sale of shares in the stock market cannot be adjusted against salary or pension. You can specify the loss under capital gains section in ITR by entering the sale consideration and Cost of acquisition. It can be carry forwarded for a period of 8 AY from the AY in which the loss was incurred. If the loss was not utilized then in the subsequent year the loss needs to be specified in the carry forward section in ITR.  
Note :
In order to carry forward loss under this head Return Of Income (ROI) needs to be filed on or before the due date u/s 139(3).
Please correct me if the above solution has an alternative view.