Final answer:
The three numerical designators required to be etched on tools refer to the significant figures marked on them, excluding leading zeros but including both distinct numbers and trailing zeros that provide specific information such as model, size, or serial number for identification and traceability.
Step-by-step explanation:
The question seems to be related to the information that must be etched on tools, specifically concerning the numerical designators required and their significance. This is a common practice in industries where tools are standardized and must comply with specific regulations or company policies regarding identification and traceability.
The details provided reference rules that appear to outline which numbers are considered significant when etching tools. Rule 1 seems to indicate that all visible numbers are significant. Following this rule, numbers that are clearly etched or marked on the tool are intended to convey important information. This might include a tool's model number, serial number, or size designation.
Rule 3 suggests that leading zeros are not significant. Leading zeros are typically placeholders and do not contribute any value to the numerical identifier. For example, '003' would be the same as '3' for the purpose of tool identification.
Finally, rule 5 indicates that trailing zeros are significant. This could be related to precision or the measurement system in use. For example, '50' might distinguish a tool from one that is simply labeled '5' because it represents a different size or capacity.