The symbol φ is usually used to indicate the diameter, such as the diameter of steel bars!
The symbol & indicates who is the same as who, for example: b: x&; y？ Φ 8 @150 means that the XY of the bottom reinforcement is the same in both directions!
; Semicolon, in the centralized annotation of plane construction drawing of reinforced beam, is a separator symbol representing upper and lower reinforcement!
/? Slant, in the plane construction drawing of reinforced beam, is a separator representing the upper and lower floors! For example, 4/5 is 4 upper steel bars and 5 lower steel bars!