β, beta    	β= v/c (4-32), see small-case "b"

ε0 	electric ?[permeability,permittivity]? in a vacuum, 
	ε0 = 8.854 187 817...  10−12 F/m (farads per metre).
	BUT  The value of ε0 is currently defined by the formula[2]
	ε0 = 1/μ0/c^2  AHHH HAH!
εr	relative static permittivity

λ , lamda 	wavelength (equ?)
λ(v) 	velocity-dependent proportionality between Ei and E0 (4-31)

μ0 	magnetic ?[permeability,permittivity]?.
	ε0 = 1/μ0/c^2  or  ε0*μ0 = c^2 
	µ0 = 4π10−7 N / A2 ≈ 1.2566370614...10−6 H / m or Tm / A or Wb / (Am) or Vs / (Am)

φ(r), phi	For Appendix A as per p179h0.25 (A-3) (A-3) and (A-8) and p180h0.45 just below (A-10) from Ampere's Law
	φ(r) = -3/2/c/|r|^2 
	But "A" drops out between p179h0.9 (A-9) and p180h0.3 (A-10) , assuming for CGS units that A/2 = 1/c  (but Lucas typically uses Gaussian units?)
	This is likely because A is "absorbed" into an arbitrary (at that point) ?
	Shorthand  PP(r)

χ(r), chi	χ(r) = i*i/c/|r|^3 from p180h0.5 (A-11)

ψ(r), psi	ψ(r) = B/|r|^2  as per p179h0.25 (A-3) from Ampere's Law,
	from p179h0.8  (A-8)  B = -3/2*A

Ω, omega  	solid angle (5-16)

θ, theta 	is the 2D angle between the plane perpendicular to v (unit vector for velocity of a POI - often of the particle in the observer frame), centered at the particle, and another point of interest(POI),  measured from the direction of v.   
	In a sense, the angle θ is like the LATITUDE of the point of interest wrt the particle. 

w, ω  	angular speed (radians/s  (Fiigure 7-2,8-1) , w1,w2 

ρ	charge density 

∇'	I'm guessing ∇' is Lucas's notation for the time gradient dp[dt: ...]
∇'	(4-28) here it is a spatial, NOT time, derivative!?!?