When a Tank punches a Hittable it adds a Glow to the hittable which all infected players can see.
this video shows how it works: https://www.youtube.com/watch?v=UZDF6dbagxU&feature=youtu.be

-command-
(l4d2_tank_props_glow.cfg in \cfg\sourcemod\ folder.)
// Three values between 0-255 separated by spaces. RGB Color255 - Red Green Blue.
// 發光顏色 紅 綠 藍 
// Default: "255 255 255"
l4d2_tank_prop_glow_color "255 255 255"

// Only Tank can see the glow
// 只讓坦克看到發光輪廓?
// Default: "0"
l4d2_tank_prop_glow_only "0"

// How near to props do players need to be to enable their glow.
// 距離多近才發光
// Default: "5000"
l4d2_tank_prop_glow_range "5000"

// Spectators can see the glow too
// 旁觀者是否也能看到發光輪廓?
// Default: "1"
l4d2_tank_prop_glow_spectators "1"

// Show Hittable Glow for inf team whilst the tank is alive
// 開啟此插件
// Default: "1"
l4d_tank_props_glow "1"