求解释

忍者22

Name : AC1PH - Steady-state (cosine) function. TYPE 14.
Card : SOURCE
Data :    U/I= 0: Voltage source. A radio button is used in newer ATPDraw versions.
              -1: Current source.
: H* d# i  B8 m5 h/ I          Amp= The peak value in [A] or [V] of the function.
' u  N- }2 N. @0 a/ b2 r            f= Frequence in [Hz].
          pha= Phase shift in degrees or seconds depending on A1.
$ ]5 A! R" @5 p. M6 Y3 H7 M6 a           A1= 0: pha in degrees.
              >0: pha in seconds.
         Tsta= Starting time in [sec.]. Source value zero for T<Tsta.
4 L* T4 F  r1 B& G: j         Tsto= Ending time in [sec]. Source value zero for T>Tsto.
! d3 O% w! X; j) aNode :     AC= Positive node of cosine function.
5 U# G2 s9 h/ ^9 F' S               Negative node is grounded.
For trapped charge functions: Specify a current source, a very low frequency, Tsta=5432. and Tsto=0.
' M& q; ]' G  f0 f  ^8 p% HRuleBook: VII.C.4
请问红色字体是啥意思？