Here are some common optical parameters for reticles: 

Size: This includes specific dimensions such as length, width, diameter, and thickness. For example, there are reticles with different sizes such as 302MM, 251MM, a diameter of 18MM, and a thickness of 1MM. 

Accuracy: This refers to the precision of the reticle manufacturing, with a common accuracy of 0.001MM.

Flatness: For instance, some reticles have a flatness of 0.01. 

Dimensional tolerance: Some reticles have a dimensional tolerance of 0.1. 

Chromium coating thickness: For example, some reticles have a chromium coating thickness of 180 nanometers. 

Chromium coating color: Colors such as yellow or brown. 

Transmittance: For reticles with a 1.5mm thick ultraviolet fused quartz substrate and chromium coating on one side, the transmittance is greater than 90% within the spectral range of 200 - 1200nm. 

Pattern line width: For example, the pattern line width of a concentric ring reticle is 10µm.