Shadow Mark Feat 2
Source Pathfinder Advanced Player's Guide
Prerequisites expert in Stealth
You have learned special tricks that help you follow individuals without them noticing you.
When you attempt a Stealth check to Avoid Notice while following a specific target, the target takes a -2 circumstance penalty to their Perception DC. If you have master proficiency in Stealth, the penalty is -3 or -4 if you're legendary.
If you start an encounter with the target while shadowing them, the target takes this penalty to their initiative roll and to their Perception DC to determine if they notice you, as normal for Sneak.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
GeneralA type of feat that any character can select, regardless of ancestry and class, as long as they meet the prerequisites. You can select a feat with this trait when your class grants a general feat.
SkillA general feat with the skill trait improves your skills and their actions or gives you new actions for a skill. A feat with this trait can be selected when a class grants a skill feat or general feat. Archetype feats with the skill trait can be selected in place of a skill feat if you have that archetype's dedication feat.