TSQL Wild Characters Query

HI, below is my query..can anyone clearly explain to me
what the following wild characters are doing ?

1) select addressee from mytable where charindex(' ', reverse(addressee)) - 1 > 0
	and len(right(addressee, (charindex(' ', reverse(addressee)) - 1))) < 2
 
2) select postcode from mytable where postcode like '[a-zA-Z][a-zA-Z] %'
 
3) select address1 from mytable where address1 like replicate('[0-9]',len(rtrim(ltrim(address1))))

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