what exactly does the bolded text mean? this is from the c450 manual
Masonry Fireplace Requirements
• The entire fireplace and chimney must be cleaned
and inspected before installation. The system
must meet local building code requirements.
• The structure and components must be free of
any defects such as cracks or broken bricks or flue
tiles. Any damage must be repaired before installation.
Any opening that may exist between the masonry
of the fireplace and the facing masonry must be
permanently sealed.
Masonry Fireplace Requirements
• The entire fireplace and chimney must be cleaned
and inspected before installation. The system
must meet local building code requirements.
• The structure and components must be free of
any defects such as cracks or broken bricks or flue
tiles. Any damage must be repaired before installation.
Any opening that may exist between the masonry
of the fireplace and the facing masonry must be
permanently sealed.