1686
But the complexity of the geometry can induce unique inspection problems like inaccesable surfaces or the absence of measuring datum planes ; 7 Application .
 concept or principle: complexity; concept or principle: geometry; process characterization: inspection; concept or principle: surfaces; process characterization: datum planes
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 concept or principle: complexity; concept or principle: geometry; process characterization: inspection; concept or principle: surfaces; process characterization: datum planes