| C | C terminus Modification |
| C00 | {-OH}, free acid group |
| C01 | {NH2}, Amidation |
| C02 | {-CHO}, peptide aldehydes |
| C03 | {-ol}, alcohol peptide |
| C04 | {CMK}, chloromethylketone |
| C05 | {FMK}, Fluoromethylketone |
| C06 | {Cya}, Cysteamide |
| C07 | {pNA},p-nitroaniline |
| C08 | {-ONP}, para-nitrophenol |
| C09 | {AMC},7-Amino-4-methylcoumarin |
| C10 | {AFC} |
| C11 | -OMe (C-terminal) |
| C12 | -OEt (C-terminal) |
| C13 | -OBzl (C-terminal) |
| C14 | -OtBu (C-terminal) |
| C15 | {-OSu}, hydroxysucinimide ester |
| C16 | -NHMe (C-terminal) |
| C17 | -NHEt (C-terminal) |
| C18 | -NHisopen (C-terminal) |
| C19 | -NH(CH2)6 (C-terminal) |
| C20 | -NHPh (C-terminal) |
| C21 | {NHEt(O)EtNH-Fmoc}, 2,2'-Oxydi Ethanamine-Fmoc |
| C22 | {NHEt(EtNH-Myr)2} |
| C23 | -NH(OMe)Me (C-terminal) |
| C24 | -TBzl (C-terminal) |
| C25 | -NHNH2 (C-terminal) |
| C26 | -ED (C-terminal), -NH-CH2CH2-NH2 |
| C27 | -BD (C-terminal), -NH-CH2CH2CH2CH2-NH2 |
| C28 | -Pyrenemethylamine |
| C29 | chloro-4-hydroxyanilide |
| C30 | 4-amino-2-Chlorophenol |
| C31 | -octyl ester |
| C32 | -ED-Fmoc |
