Qualified Leasehold Improvement Rules

[Drand1]

I'm having trouble interpreting the rules of Qualified Leasehold Improvement equipment eligible for Section 179. The rule states:

• The improvement is made under or according to a lease by the lessee or the lessor of that part of the building
• That part of the building is to be occupied exclusively by the lessee of that part.
• The improvement is placed in service more than 3 years after the date the building was first placed in service by any person.
• The improvement is section 1250 property.

The rule I'm having trouble with is, if the improvement is made under or according to a lease. Does this mean the lease agreement has to specifically state the improvement being made in order for it to qualify. Or, would it still qualify if the lease agreement had a vague statement allowing the lessee to make improvements?

Thanks