All I could find online was videos, which don't make much sense for this achievement. I prefer bullet points. Here is a list of all the optional objectives in each mission:
San Celini (2) Choking the Checkpoint –
Clear the checkpoint That’s a Wrap –
Destroy the cameras (3x) Bitanti Village (3) A Late Message –
Search the Graveyard Signal Advantage –
Find the radio operator before he calls for help [MH] The Towering Assassin –
Kill the sniper [MH]Regilino Viaduct (5) Hidden in Plane Sight –
Find the downed American pilot; Find the crashed observation plane [MH] Depot Destruction –
Destroy the Nazis’ transport depot The Big Bang Theory –
Locate and destroy the additional ammo dump; Find the ammo cache and destroy it [W] Checkpoint Checkmate –
German checkpoints cleared (2x) Destroy the Armored Car –
Destroy the Sd.Kfz. 222 Armored Car Lorino Dockyard (4) Shots in the Dark –
Locate the typhus vaccines Assassination –
Kill the corrupt Harbormaster Rapid Response –
Destroy the armored threat (2x) Hello to Arms –
Raid the German armory [MH]Abrunza Monastery (3) Annihilate the Artillery –
Destroy the artillery guns (3x) [W] Art Appropriation –
Kill and search officer for radio code; use radio code to signal convoy; identify the truck with the art on it; ring the church bell to signal the mafia The Abbot’s Story –
Find the documents (4x)Magazzeno Facility (3) Crack the Code-Breakers –
Acquire intercept digest documents (2x) [W] Enigma Variations –
Wreck the code-breaking center [W] Naval Gazing –
Destroy the German naval guns (5x); Assassinate the officer in charge of defenses [MH]Giovi Fiori Mansion (2) The Nazi Propaganda Machine –
Find route of propaganda truck; Destroy truck [MH] Weakening Defenses –
Neutralize MAS patrol boat; Destroy encampments (3x)Allagra Fortress (2) Intercept Course –
Grab the Nazi missile strategy Mischief-Maker –
Sabotage the missiles (5x) [W] – Weaver specific side mission (for achievement “Weaver’s Warrior”)
[MH] – Mother Hen specific side mission (for achievement “Mother Hen Knows Best”)