Q81 and Q99 hint text updates (#2905)

2025/26 copy changes

config/locales/forms/2025/sales/sale_information.en.yml

@@ -44,7 +44,7 @@ en:
           staircasesale:
             page_header: ""
             check_answer_label: "Part of a back-to-back staircasing transaction?"
-            hint_text: ""
+            hint_text: "Back-to-back staircasing transactions are used as a way for shared owners who own less than 100% of their property to sell on the open market. It involves the shared owner purchasing the remaining share from their landlord and immediately selling 100% of the property to a buyer on the open market. The landlord is then reimbursed for the staircasing transaction through the proceeds of sale to the buyer."
             question_text: "Is this transaction part of a back-to-back staircasing transaction to facilitate sale of the home on the open market?"
 
           firststair:
@@ -213,7 +213,7 @@ en:
             page_header: ""
             has_mscharge:
               check_answer_label: "Does the property have any service charges?"
-              hint_text: "For example, service and management charges"
+              hint_text: "This includes any charges for day-to-day maintenance and repairs, buildings insurance, and any contributions to a sinking/reserve fund. It does not include estate management fees."
               question_text: "Does the property have any service charges?"
             mscharge:
               check_answer_label:  "Monthly leasehold charges"