English Bus/Financial Business/Commerce (general)

In the sample paragraphs below, does this phrase mean something like "undertake to be a guarantor"?

"Unless so authorized or ratified by the Board of Directors... no officer, agent or employee shall have any power or authority... to pledge its credit or to render it liable for any purpose or for any amount."

"Q. What Does Private Activity Bond - PAB Mean?
A. Tax-exempt bonds issued by or on behalf of local or state government for the purpose of providing special financing benefits for qualified projects. The financing is most often for projects of a private user, and the government generally does not pledge its credit."

"Neither the state nor any county, school district or municipality... shall... lend or pledge its credit or make any donation to or in aid of any person, association or public or private corporation or in aid of any private enterprise for the construction of any railroad except as provided in Subsections A through F of this section."