We have a separated accounting standard, AASB 138, that specifically deal with intangible assets

Question 1

We have a separated accounting standard, AASB 138, that specifically deal with intangible assets and it provides different requirements from those for property, plant and equipment (the rules for which appear in AASB 116). What is about intangible assets that require them to have a separate accounting standard? Do you think the differences in requirements are logical? (Up to 300 words)