Corrosion level.. die die mz memorize

hi.. here's some information regarding corrosion level. do memorise it.. thankx
i read it from IN SIA51/001. however very chim. so i decided to rephase myself from the diagram above. hope you guys understand what i m writing

a. Level 1 corrosion -
-->Corrosion found due to acid or mercury split;
-->Corrosion which is not widespread and does not required reinforcement or replacement;
-->Corrosion which is widespread and the blendout is within allowable SRM limit;
-->Corrosion which is widespread and the blendout is approaching allowable SRM limit but the
corrosion damage is found over multiple inspections;
-->Corrosion was removed after cumulative blendout until out of SRM limit and cause structure
need reinforcement.

b. Level 2 corrosion -
--> One time inspection and found widespread corrosion and the blendout approach SRM limit;
--> Corrosion one time blendout out beyond allowable SRM limit

c. Level 3 corrosion -
--> any corrosion which is airworthiness concern. (operator/ manufacturer)

Regards,
PTF