S5.3.4 When an indicator lamp is ac

S5.3.4 When an indicator lamp is activated it may be steady burning or flashing.S5.3.5 (a) Each indicator lamp shall display word, words or abbreviation, in accordance with the requirements of Standard No. 101 (49 CFR 571.101) and/or this section, which shall have letters not less than 1⁄8 -inch high and be legible to the driver in daylight when lighted. Words in addition to those required by Standard No. 101 and/or this section and symbols may be provided for purposes of clarity.(b) If a single common indicator is used, the lamp shall display the word “Brake”. The letters and background of a single common indicator shall be of contrasting colors, one of which is red.(c)(1) If separate indicators are used for one or more of the conditions described in S5.3.1(a) through S5.3.1(g) of this standard, the indicator display shall include the word “Brake” and appropriate additional labeling, except as provided in (c)(1) (A) through (D) of this paragraph.(A) If a separate indicator lamp is provided for gross loss of pressure, the words “Brake Pressure” shall be used for S5.3.1(a).(B) If a separate indicator lamp is provided for low brake fluid, the words “Brake Fluid” shall be used for S5.3.1(b), except for vehicles using hydraulic system mineral oil.(C) If a separate indicator lamp is provided for an anti-lock system, the single word “Antilock” or “Anti-lock”, or the abbreviation “ABS”, may be used for S5.3.1(c).(D) If a separate indicator lamp is provided for application of the parking brake, the single word “Park” may be used for S5.3.1(d).(E) If a separate indicator is used for the regenerative brake system, the symbol “RBS” may be used. RBS failure may also be indicated by a lamp displaying the symbol “ABS/RBS.”(2) Except for a separate indicator lamp for an anti-lock system, a regenerative system, or an indicator for both anti-lock and regenerative system, the letters and background of each separate indicator lamp shall be of contrasting colors, one of which is red. The letters and background of a separate lamp for an anti-lock system, a regenerative system, or a lamp displaying both an anti-lock and a regenerative system shall be of contrasting colors, one of which is yellow.