What is referred to in accounting as a single-line consolidation?

Consolidations imitate family trees.
Single line Consolidation is the consolidation
Of subsidiaries ONLY having no sub-subsidiaries.
Children only NO grand-children.

Actually single- Line Consolidation or One - Line consolidation is the equity method of accounting. When you own from 20-50 % of a company you usually apply the equity method for your investment in associate. When the associate has net income for 100,000 and you own 30% of it. You will record a revenue account called equity in income of an associate for the amount of 30,000. So you will have only one line. That's why its called single-line. In the contrary when you own more than 50% of a subsidiary you will perform what's called consolidation and you will aggregate all revenues and expenses account with the revenues and expenses accounts of the subsidiaries. So its not a single line.