Here is the sample of MAP file from my test project...
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0001:001EFC14 00000020 C=CODE S=.text G=(none) M=Vcl.CategoryButtons A
It mean that your asm code of your unit MainU
start at $00232C28 address and the length of compiled unit is $00006998 bytes.
The segment class (C=) is CODE, defined at beginning of map file.
The segment name (S=) is .text
The segment group (G=) is none.
The segment module (M=) is MainU
The ACBP attribute = A9 mean:
Check also: http://files.mpoli.fi/unpacked/software/programm/general/ss0288.zip/ss0288_4.txt