What the law requires
Regulation (EC) No 852/2004, Annex II, Chapter IX says food that can support the growth of harmful bacteria must not be kept at temperatures that may cause a risk to health. Article 5 requires HACCP procedures with critical limits, monitoring, corrective actions and records that fit the size of the business. In the UK, the Food Standards Agency pack Safer food, better business has the same kind of hot holding checks. The minimum temperature and how often you measure come from your own HACCP plan and the national guide.
Write the minimum hot holding temperature from your HACCP plan at the top of the sheet. It depends on the rules in your country.