Simplified:

On the HSK 1 vocabulary list, at CEFR level A1.

háo ㄏㄠˊ

    • to wail to howl

      bound form

hào ㄏㄠˋ

    • to call out to command

      literary

    • bugle trumpet

      bound form

    • signal bugle call (e.g. 起床號|起床号[qi3 chuang2 hao4])

      bound form

    • mark sign

      bound form

    • to mark to label to assign a number
    • name appellation (e.g. 國號|国号[guo2 hao4], 年號|年号[nian2 hao4], 遼寧號|辽宁号[Liao2 ning2 Hao4])

      bound form

    • number designation (e.g. 237號房間|237号房间[er4 san1 qi1 hao4 fang2 jian1] "Room 237")

      after a numeral

    • day of the month (e.g. 七號|七号[qi1 hao4] "the 7th")
    • size type category (e.g. 五號電池|五号电池[wu3 hao4 dian4 chi2])

      bound form

    • to feel (the pulse) (used in 號脈|号脉[hao4 mai4])

      TCM

    • classifier for numbered people or items

Where 號 is used

Sources