Sentence:  Scarcity of paper caused many Southerners to adopt the practice of cross writing , i. e. , after writing from left to right of the page in the <WSD>usual</WSD> manner , they gave the sheet a half turn and wrote from end to end across the lines previously written . 
Meaning of the word marked with <WSD> tags:  occurring or encountered or experienced or observed frequently or in accordance with regular practice or procedure