Possible Clues:

• Most strictly speaking to the south of the highest
• Extremely serious letter indicative of owning top location
• The southern side of the highest peak is the most challenging
• Very strictly speaking, the South gets over the highest
• Thou cuttest this off most strictly
• Very strictly speaking, the South is over the highest point
• Very strictly speaking, it's South as high as you can go
• How thou cuttest in a very harsh manner
• It's very like 27 across and very high at last
• Most harsh and punitive