You may add designation, date of joining, full address with contact details of joining location, details of documents that are required to be submitted by candidates (salary proof, relieving letter, etc), duty timings, leave, (work timing), working days, weekly -off day
salary and allowances, department/section, punctuality and attendance, period of probation and confirmation, salary of confirmation (if applicable), transferability of services, Notice of Termination or separation, confidentiality, reporting relationship, General, etc. You can also put few most important clauses of Certified Standing Orders of your company (in the absence of which Model Standing orders by Govt).